Students practice skip-counting (by 2s, 3s, 5s, and 10s) and fill in missing numbers in sequences such as 2, 5, 8, __, __, __ and 1, __, 3, __, 5, __. Students place numbers on a 1–100 number grid and identify the number before and after a drawn card (e.g., say thirty-four and thirty-six for 35). Students use a number line to fill in missing entries when counting by given increments and reassemble partial grid pieces to restore numeric order.

Students practice mentally adding and subtracting 10 (and 100 in the skills list) from numbers using counting-on and counting-back by tens (Activities 1–3, Day 2). Students use an interactive 1–100 number grid and an abacus to check answers and to show place-value moves when they add 10 (move beads across rows) or count up/back by tens. Students complete patterned worksheets and card-draw activities that require them to record sequences formed by adding or subtracting 10 and solve word problems that add tens repeatedly (e.g., Kevin reads 10 books each month).

Students create and name arrays (e.g., 4 by 3, 2 by 6) and translate those arrays into repeated-addition number sentences such as 3+3+3+3=12 and 4+4+4=12. Students use manipulatives and sticky notes to record row or column totals (for example placing 6 and 6 to produce 6+6=12) and complete worksheets that require writing two addition sentences for each array. Students generate arrays from dice rolls and draw arrays, then write the corresponding addition sentences for each configuration (examples and answer keys show arrays for numbers like 8, 12, 16, 20, 24).

Students practice multiple addition strategies: they make arrays and write number sentences (3+3+3=9), use number lines to add (draw hops from 4 to 7), count with counters and fingers, and use an abacus to add (e.g., 4+3, 5+5, 8+7) including regrouping to tens. The commutative property is taught and practiced by having students show 4+3 and 3+4 with counters, dominoes, and dice and record turn-around facts. The abacus activity explicitly has students group fives and tens (moving beads to show 8+7 → 15), demonstrating a place-value based strategy.

Students practice addition number sentences using drawings, counters, an abacus, and whiteboard strategies (Activities 1, 3, 5, and 6). Students solve and create addition word problems, identify addition clue words, and work on missing-addend problems such as 2 + ___ = 5 and the beanbag toss missing-addend option (Activities 2, 3, and 5). Students work toward fluency with sums to 20 using addition flashcards and are asked to memorize single-digit sums (Activity 7).

Students solve many two-digit subtraction problems (e.g., 18-7, 22-10, 15-9, 13-8) using objects, number lines, fingers, the abacus, and written vertical/horizontal number sentences. Students are asked to list addition strategies and try those same strategies for subtraction, and they use the abacus procedure of moving beads to represent subtracting. Students practice subtraction in games (Bowling for Differences), card draws, and a kitchen estimation task, and they identify 1 more/1 less and 10 more/10 less for two-digit numbers.

Students solve one- and two-step subtraction word problems within 100 (e.g., 12-10, 15-10, 90-80) by writing completed number sentences and labeling answers. Students use and are asked to try different strategies such as fingers, drawings, counters, and number lines to find differences. Students generate their own subtraction word problems from given number sentences and write subtraction number sentences for menu/real-world price problems.

Students practice and explain the identity/zero property through the "Working With Zero" sheet (e.g., 22 + 0, 22 - 0, 0 + 12) and flashcard drills that include zero facts. Students learn and practice properties and relationships such as commutativity (turn-around facts) and work with doubles, doubles-plus-one, and near-doubles on dedicated activity pages and foldables. Students use place-value related tactics for making tens (abacus work with two 5s, dominoes that sum to 10, Circles of Ten, and games like Taking 10) to restructure addends to find sums quickly.

Students practice addition and subtraction facts through timed "Fact Power" sheets and record speed and accuracy (Fact Power 1 sheet and Fact Power Record). Students generate the four related number sentences for fact families (e.g., 2+3=5, 3+2=5, 5-2=3, 5-3=2) and explicitly use the relationship between addition and subtraction. Students make and use triangular fact-family cards, play matching/concentration games, and use online games that provide repeated practice with sums and differences up to 20.

Students practice addition and subtraction facts with the timed "Fact Power 2" sheet and its answer key, working problems that include single- and some double-digit sums and differences. Students solve contextual two-step and one-step addition/subtraction problems in the "A Day at the Fair" activities, adding and subtracting ticket costs up to 20 and sometimes combining items. Students explore decomposition and properties of operations in Activity 3 ("How Many Ways"), where they generate all addition sentences for a given total and consider turn-around facts and use of 0.

Students complete timed "Fact Power" sheets that present addition and subtraction problems (many involving sums to 18 and differences to 0) to build calculation speed and accuracy. The project requires students to include two addition problems, two subtraction problems, and an array in their ocean-adventure story, and to record answers on an answer sheet. The skills list explicitly notes fluency in basic facts (knowing all sums of two one-digit numbers) and using addition and subtraction within 100 to solve word problems.

In the Introduction students are given 10 random addition and subtraction flashcards and asked to continue determining which facts they know and to review ones they did not know previously. The lesson also has students count and record quantities using tally marks on the "Shapes Around Me" activity, which involves working with small whole-number counts.

Students are asked to count from 40 to 80 by 2s and to review counting by 10s to 100, which practices number sequences and place-value awareness. The lesson directs the teacher to give the child 10 random addition and subtraction flashcards and to continue practicing those problems started in a prior lesson. The wrapping up activity asks students to pick two number cards from 1–100 and decide which is greater and which is less, promoting number comparison within 100.

The Shape Scavenger Hunt asks students to use tally marks to note how many of each shape they find and to write the total number for each shape in the correct column. The follow-up questions ask students to compute combined totals ("How many triangles and circles did you find altogether?") and to compute a difference ("What's the difference between the number of squares and the number of rectangles that you found?"). Students also record counts and locations on the activity page, providing opportunities to add and subtract concrete counts.

Students are asked to practice 10 random addition and subtraction flashcards and review those they still need to master. They are reminded of and asked to use strategies such as turn-around facts/commutative property, doubles, doubles plus one/two, fact families, and making 10 (including using two fives to make 10). Students are encouraged to identify which flashcards correspond to these strategies and to sort and practice facts with the strategies in mind.

Students practice adding and subtracting 1 and 10 in the Getting Started section (e.g., asked what is 1 more/1 less/10 more/10 less for 54 and 31). In Activity 2 students decompose numbers into tens and ones and write sums in expanded form (for example, 30+5=35, 20+9, 60+1), explicitly linking place value to addition. Several activities have students build numbers from tens and ones and compare numbers using the digits in the tens and ones places, reinforcing place-value reasoning.

Students practice mental addition within 100 through multiple activities: mentally adding multiples of 10 (Activity 1 and 2), using base-10 blocks and an abacus to add two-digit numbers and show regrouping (45+20 example, Two-Digit Addition page), and playing Race to 100 to compose tens. The lesson teaches and has students use place-value strategies (counting by tens, composing 10, place value mat) and properties of operations (Zero Property, Commutative Property, Doubles, Doubles Plus 1, and Fact Families) as explicit strategies to find sums.

Students practice adding one- and two-digit numbers within 100 using mental strategies (e.g., pages and activities with problems like 59+3, 39+3, 68+5). The lesson explicitly teaches place-value based "take-and-give" (make-ten) strategies for adding 9s and 8s, and it prompts students to use the commutative property (turn-around facts) and explain which strategies they used. Students use an abacus to model and check sums and are asked to solve problems mentally and write intermediate steps (e.g., rewrite 59+3 as 60+2).

Students practice subtracting within 100 using place-value tools (base-10 blocks and an abacus) when they model and solve problems like 35-10, 57-22, and 68-35. Students use strategies tied to place value and operations such as subtracting tens mentally, counting back on number lines, and counting up to find differences (e.g., 12-8 illustrated with a number line). Students are prompted to explain which strategies they used and to record subtraction examples for strategies like role of zero, number minus itself, neighbors, and half facts.

The lesson's Skills section explicitly lists "Add and subtract two-digit numbers." In the Introduction students are asked to evaluate and correct vertical subtraction sentences (86-42, 67-45, 54-21). The Wrapping Up asks students to solve 35+14 and 76-25 and allows them to use manipulatives of their choice. Throughout the activities students represent numbers with base-10 blocks and place-value mats, which can be used to perform two-digit operations.

Students create addition sentences by drawing two number cards (1–50), write the sums in two orders (e.g., 34+15 and 15+34), and find answers using materials or strategies of their choosing. Students solve subtraction problems within 100 during the wrap-up (39-26, 15-4, 48-44). The lesson explicitly lists 'Add and subtract two-digit numbers' as a skill and has extensive place-value practice using base-ten blocks, place-value cards, and digit-value questioning.

Students count up and back by tens from two-digit and three-digit starting points (e.g., count by 10s from 30 to 100 and from 110 to 200) and fill in missing multiples of ten on number grids. Students use base-ten blocks and a place-value mat to add 10 to 180, physically add ten-rods, recognize ten tens equal one hundred, and trade ten rods for a hundred flat to make 200. Students complete exercises that require identifying numbers that result from adding or subtracting tens (e.g., filling blanks 370, 380, 390, 400…).

Students practice two-digit addition and subtraction in multiple activities (Box 7 Dicey Two-Digit Addition and Subtraction; Box 8 Close Call: Two-Digit Addition; Box 9 Close Call: Two-Digit Subtraction) by creating two-digit numbers from dice or cards and computing sums or differences across repeated rounds. Students are prompted to use manipulatives (base-10 blocks, abacus) and to "think aloud" about their process, with explicit prompts to begin adding in the ones place and to carry to the tens place. Activities require students to arrange digits strategically (e.g., place higher digits in the tens place to maximize sums) and include reminders to start subtraction with the larger numbers in the ones and tens places.

Students complete number-grid tasks that require counting by 10s and 5s and locating numbers on a 1–100 grid (e.g., count by 10s starting at 4; count by 5s from 55 to 75). Students are asked to identify numbers that are 10 more or 10 less than a given number and to find numbers that are 20 more and 40 more than given numbers (e.g., 10 more than 63, 20 more than 19, 40 more than 32). These activities require students to use place-value understanding to add or subtract multiples of ten within 100.

Students count up and down by tens on number grids (e.g., pick a number 1–10 and count by 10s to 200; count down by 10s from 191–200). Students add and subtract single inches when measuring lines (e.g., asked how long a 5-inch line would be if one inch is added or erased). Students combine measurement pieces to form sums (e.g., put 3- and 6-inch or 4- and 5-inch straws together to make 9 inches) and are asked to add 20 to a chosen number between 150 and 170.

Students are given four vertical addition and subtraction problems within 100 (34+25, 76-23, 56+18, 98-83) and are asked to use strategies and methods of their choosing to find the sums and differences. Students complete number grids (301–400) with prompts to identify digits and the values in the hundreds, tens, and ones places. The skills list explicitly includes reading and writing numbers to 1000 and understanding that digits represent hundreds, tens, and ones.

The Wrapping Up section asks students to point to numbers that are 1 more, 10 more, 1 less, and 10 less than given numbers and to count odd/even numbers in ranges, which requires adjusting numbers by ones and tens. The Skills and Introduction prompt students to read and write numbers to 1000 and to understand that three digits represent hundreds, tens, and ones, and students complete number grids counting by hundreds. Activity prompts asking for identification of an inch, a foot, a centimeter, and a meter also require students to compare and reason about numeric measures.

Students are asked to compute four vertical number sentences within 100 (89 - 17, 56 - 24, 29 + 55, 36 + 45) and told to use strategies and materials of their choosing to find the sums and differences. The lesson has students practice counting by 10s and 100s and asks which digit changes, and students complete number grids and read/write numbers to 1000, reinforcing place value understanding. The Skills list explicitly includes "Read and write numbers to 1000" and "Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones."

The Skills list explicitly states students will "use addition and subtraction within 100 to solve word problems involving lengths that are given in the same units." Activity 1 asks students to measure objects and then write subtraction sentences to find differences, with a prompt that subtraction sentences should begin with the larger number and that students may use a strategy of their choosing. Activity 2 has students repeatedly measure cut ribbons and write subtraction sentences (for example, "9 in. - 7 in. = 2 in.") to find differences between lengths.

The Skills list explicitly tells students to use addition and subtraction within 100 to solve word problems involving lengths given in the same units. In Activity 2, students select 7 gummy worms, measure lengths before and after stretching, and are asked to find the differences by subtracting each pair of measurements, using tools (whiteboard, abacus, counters) and strategies of their choice. Activity 4 and the Measurement Line Plot give additional practice measuring and recording numerical lengths that are then used in plotting and counting frequency.

The Skills section explicitly says students will "Use addition and subtraction within 100 to solve word problems involving lengths that are given in the same units." Activity 2 has students write number sentences and find sums or differences for concrete measurement word problems (e.g., 3+6, 4+6, 11-5, 12-9, 15-8, 29-26). The activity prompts students to draw pictures and use counters or an abacus to solve those problems and to label answers with measurement units.

Students complete an "Adding and Subtracting Two-Digit Numbers" activity with six problems (48+20, 67-30, 67+9, 78-34, 8+46, 90-40) and are asked to explain the strategies they used. Students use place-value tools (abacus and base-10 blocks) to model tens and ones and to exchange groups of ten (e.g., showing 60+40 and exchanging 10 tens for 1 hundred). Students break numbers into tens and ones (expanded form) to add (e.g., 35+23 as 35+20+3) and are prompted to use properties of operations, including the Commutative Property/turn-around facts, when adding multiple addends.

Students create and solve multi-addend addition sentences (three and four addends) using a number generator and laminated grid paper. Students practice many two-digit subtraction problems and are instructed to align ones and tens, use base-10 blocks, and begin subtraction with the ones place (Activity 1). Students model and perform borrowing/regrouping with base-10 blocks and a place-value mat (Activity 2 and Day 2), then translate that borrowing to paper representations. Students use fact families and addition to check subtraction answers (Activity 4).

Students draw two number cards (1–99) and create both an addition sentence and a subtraction sentence, write each on grid paper, and find the sum and the difference. Students are encouraged to find answers without manipulatives (mental strategies) and are allowed to use base-10 blocks, a place-value mat, or an abacus if needed. The instructions remind students that they may need to regroup or borrow as they work, which directs them to use place-value procedures when computing.

Students practice adding and subtracting tens and hundreds using an interactive abacus where they repeatedly add/subtract 10 and 100 and observe place-value changes. The Student Activity Page requires students to compute +10, +100, -10, and -100 for a list of three-digit numbers, and students are asked to mentally add/subtract 10 or 100 to numbers 100–900. The wrap-up directs students to play an addition game set to "sums to 100," providing additional practice with addition within 100.

Students solve a two-digit addition problem (35+47) and are prompted to use place-value reasoning, composing 10 and regrouping, and to explain each step. Students are shown expanded form (300+20+1, 400+30+4) and asked to add by place value for multi-digit sums (e.g., 321+434). Students use concrete place-value tools (base-10 blocks and an abacus) to model addition and to check sums, and the starter activity has students add and subtract 10 and 100 from randomly generated numbers.

Students use base-10 blocks and laminated place-value mats to add and subtract three-digit numbers (e.g., 453-138, 684-432) and are asked to subtract multiples of 100 by reasoning about changes in the hundreds place (e.g., 568-200, 683-500). Students play the Close Call subtraction game creating three-digit subtraction sentences and discuss strategies such as keeping hundreds digits close and lining up place values. Students practice borrowing (regrouping) with manipulatives and are prompted to begin subtraction in the ones place and to check whether borrowing is needed.

Students create and reason about place-value numbers by drawing ones, tens, and hundreds cards and answering questions such as "What is 10 more?" and "What is 10 less?" Students use base-10 blocks, an abacus, place-value mats, and are prompted to talk aloud about strategies (for example, starting in the ones place and carrying to the tens) while making and adding numbers in the Close Call addition game. The lesson also asks students to complete a worksheet of addition and subtraction problems with three-digit numbers and encourages use of mental math and place-value strategies. A web link is provided that directs students to an online game where they can choose "sums to 100."

Students complete addition and subtraction practice that includes two-digit problems such as 67 + 75 and 91 - 78. Students are encouraged to use mental math, manipulatives, and are reminded about composing 10/regroup and borrowing and to line up place values. Students can play the Snowball Smash game set to "Subtract a 2-digit number from a 2-digit number," providing targeted two-digit subtraction practice.

Students practice adding minutes by counting by fives around a large floor clock, placing 00, 05, 10...55 index cards and repeatedly adding 5 minutes as they move the minute hand (Activity 1 and 2). Students sequence and read times in five-minute increments in the "Sequencing 5-Minute Times" and maze activities, which requires repeatedly adding or recognizing successive five-minute additions. The Wrapping Up section has students write vertical number sentences and compute sums and differences (e.g., 617+175, 853-175), showing they perform addition and subtraction computations.

Students answer timed‑duration problems on the "Swimming Problems" pages that require adding minutes (e.g., "How long altogether did Karen, Greg, and Ally swim laps?") and subtracting minutes (e.g., "How much longer did Emmy swim laps than Scott?"). The instructions explicitly allow students to use manipulatives such as an abacus, base‑10 blocks, or a whiteboard as they compute, which supports place‑value reasoning. Activity 1 also has students compare and order activities by duration and match activities to time amounts (5, 15, 30, 60 minutes).

Students are asked to combine activities whose durations are given in hours, half hours (30 minutes), and quarter hours (15 minutes) and to place them into one-hour blocks (Step 3 and Step 4). Students create a 'Ways to Make an Hour' list (1 hour; 2 half hours; 4 quarter hours; 1 half hour and 2 quarter hours) and use a geared clock to count quarter-hour increments. Students are prompted to "prove" that activities in each hour block add up to an hour and to identify which 30-minute or 15-minute activities pair or combine to make larger time amounts.

Students repeatedly add coin values to find totals (Activity 2 asks them to count 3 dimes, 2 nickels, and 4 pennies to get 44¢ and other totals up to 70¢). The lesson has students count by 10s and 5s and asks about the digit in the tens and ones places when counting by tens/fives, supporting place-value strategies. Students perform equivalence exchanges (5 pennies = 1 nickel, 2 nickels = 1 dime) and use these exchanges to make amounts with the fewest coins (Activity 4 and Wrapping Up).

Students add coin amounts in the Introduction by naming and writing totals for groups such as 6 dimes, 2 nickels, 3 pennies (73¢) and are prompted to count dimes by 10 and then add another 10 for two nickels. In Activity 1 students repeatedly add pennies rolled on a die, count their total cents, and exchange 5 pennies for a nickel or 10 cents for a dime, practicing addition and grouping. Activity 3 has students use base-10 blocks and an abacus to determine values of 1–4 quarters (25¢, 50¢, 75¢, 100¢), and Activity 4 asks students to match coin groups to totals under 100¢ (e.g., 38¢, 55¢, 46¢), requiring them to compute sums of coin values.

Students add coin values to make specific totals under 100 in Activity 2 (e.g., assembling 99¢ as 3 quarters, 2 dimes, 4 pennies). In Activity 3 students cut out groups of coins, figure the value of each group, and write those values (adding coin amounts within 100). In Activity 4 students collect pennies and exchange to reach 100 cents, repeatedly adding coin amounts during play.

Students calculate totals of coin paths to match given target amounts (e.g., 87¢, 68¢, 54¢, 71¢) by adding quarters, dimes, nickels, and pennies. Students match people's coins to sticker prices (e.g., 93¢, 79¢, 63¢, 76¢) and complete 'What's in My Wallet?' riddles by drawing coin combinations to reach totals under 100¢ (e.g., 60¢, 95¢, 76¢, 64¢). Students play an online counting-coins game and use real coins as manipulatives while composing cent amounts, providing repeated addition practice within 100¢.

Students cut, sort, and glue coins to show that different collections (1 dollar bill, 4 quarters, 10 dimes, 20 nickels, 100 pennies) total 100 cents and count the dimes by 10s and nickels by 5s to prove the totals. Students build and match dollar-and-cent amounts (e.g., $1.25, $1.45) by selecting and combining coins and bills to reach specified amounts. Students write and interpret dollar notation ($1.00, $1.25) and represent those amounts with concrete coin combinations.

Students count and write coin totals such as 75¢, $1.43, $1.60, and $1.49 by combining coin values. Students play the Rolling to Two Dollars game where they add coin amounts (1, 5, 10, 25 cents) each turn and exchange coins for higher denominations, and they use a hundred flat to connect 1 dollar = 100 cents. The materials encourage counting by 10s and 5s and beginning with the highest-value coins when totaling amounts.

Students practice subtraction within 100 in Activity 3 where they roll dice to generate two-digit cent amounts, write the smaller and larger amounts in cents, and determine "how much more" is needed (e.g., 26¢ to 53¢ → 27¢). Students use coins to build amounts and add coins one at a time to reach targets (e.g., adding coins to 25¢ to make 50¢), and they play web games that require matching coin combinations to given amounts. The Skills list and wallet riddles require students to show equivalent monetary amounts and make exchanges between coins and bills.

Students repeatedly count and combine coin values when they play the money exchange game, collecting pennies and exchanging them for larger coins or bills so they always have as few coins as possible. Students complete the "My Piggy Bank" page by coloring coins, then count how much money they have colored and write the total in cents/dollars. Students practice grouping by place value when asked to count half-dollars (pairing two half-dollars to make one dollar) and create amounts such as $3.64 from dice rolls and represent those amounts with bills and coins.

The Skills list asks students to count cent and dollar amounts and to solve word problems involving bills and coins, which requires combining coin and bill values. Examples of student tasks include matching pictures of coins with their amounts, matching collections of coins with their total amounts, and using the provided "Project Coins and Bills" cutouts to show money amounts. The Cereal Box Requirements include a space that shows coin values and a space that teaches how to write cent and dollar amounts, so students practice representing and totaling money.

Students are asked to add and compare counts from pictographs and tally charts (for example, "How many tables and chairs in all?", "How many dressers and shelves in all?", and "How many more chairs than beds?"). Students must add counts from the Favorite Sports tally (e.g., find how many people like tennis and soccer combined from tallies of 6 and 7) and answer comparison questions about which category has the most or fewest. Students also practice counting by tens when interpreting the flower pictograph where each flower represents 10 (e.g., identifying 20 and 60).

The lesson's Skills section explicitly says students will "solve simple put-together, take-apart, and compare problems using information presented in a bar graph," which corresponds to addition and subtraction contexts. Students read and interpret numeric values on bar graphs (e.g., identifying 20, 55 and recognizing numbers between tick marks) and work with graphs that use scales up to 100. In Activity 4 students plot and read numeric data (values up to 50) and the wrap-up game asks students to fill in missing numbers on a scale, reinforcing working with two-digit quantities.

Students are asked to read a categorical line plot and answer questions that require combining counts (for example, "How many birds and fish do students in this class own? (5)"), which requires adding 3 + 2. Students complete a Measurement Line Plot activity in which they measure lines, mark Xs on a number line labeled 1–6, and thus count frequencies for each measurement. The provided answer key shows explicit frequency counts above each number (for example, 4 Xs above 1, 5 above 2, etc.), so students practice counting and totaling occurrences from the plot.

The lesson explicitly instructs students to "solve simple put-together, take-apart, and compare problems using information presented in a bar graph," which requires them to add and subtract counts. Students collect data with tally marks and count category totals on their Data Collection sheets. Students also decide on numeric scales for bar graphs (counting by 1s, 2s, or 5s) and answer comparative questions such as which group shows the most or least.

The lesson explicitly asks students to mentally add and subtract 10 and 100 to and from given numbers in the Skills section ("Mentally add and subtract 10 and 100 to and from a given number 100-900"). The Introduction contains specific student tasks that require finding numbers that are 10 more/less or 100 more/less than given numbers (e.g., "Which number is 10 more than 746?" and "Which number is 100 more than 93?"). The expanded form and comparison activities require students to decompose numbers into hundreds, tens, and ones, supporting use of place value reasoning.

Students practice skip-counting by tens and hundreds and solve addition and subtraction problems that involve tens (e.g., 39 + 50, 78 - 30, 45 + 20). Students explain which place value changes when adding or subtracting multiples of 10 and 100 (e.g., 456 + 30 changes the tens place) and may use base-10 blocks to model the operations. Students are prompted to use place-value reasoning when computing sums and differences of multiples of 10 and 100 and to notice the role of zero in place value.

In Activity 5.1 students handle a group of fifty items, split them into groups of ten, and select the correct number word after items are removed or grouped (e.g., pulling out 7 from a ten, combining groups to make twenty, pushing one group away to make thirty). The activity has students physically combine and remove groups of tens and choose corresponding number-word cards, which models composing and decomposing tens and counting within fifty.