Students use number bonds and manipulatives to break numbers into parts and make wholes (Activity 3 shows examples such as 1+3=4, 2+3=5). Activity 4 has students model combinations with base-10 unit blocks and explicitly lists both orders for pairs (e.g., 4 and 1, 3 and 2, 2 and 3, 1 and 4). Students are asked to find a missing part when given a whole and one part (e.g., given 4 in the whole and 1 in a part, determine the other part), which practices thinking about addition and its inverse.

Students use an abacus and move beads to show that 6 is 5 + 1 and to show 7–10 as 5 plus another addend (Activity 8). Students recite and practice the Number Chant lines such as "6 is 5 and 1" and "7 is 5 and 2," reinforcing decomposition of numbers into 5 + n. Students complete the "Combining With 5" sheet by drawing or adding beads to make specified totals, practicing adding on to 5.

Students create and use number bonds to 10 (Activity 5) by rolling dice, recording parts in the small circles and the whole in the large circle. Students build Ten Chains (Activity 6) and use the abacus to identify pairs that combine to make 10, recite the making-10 chant, and physically model pairs like 1+9, 2+8, etc. Students solve and create story problems (Activities 8–10) that combine two groups of objects to find totals to 10 using manipulatives and drawings.

Students decompose numbers 11–20 into 10 and additional ones (skill listed and practiced) and represent 11 on the abacus by moving 10 beads on one row and 1 bead on the next. Students color beads, draw collections, and use the abacus to show numbers 11–15 (Activity 2 and Activity 3). In the money work, students combine coins to make amounts (e.g., show 13 cents as 2 nickels and 3 pennies) and make 10 by combining two nickels and exchanging nickels for pennies to verify 10.

Students decompose numbers 11–20 into 10 and remaining ones using number bonds (they draw a number in the large circle, use the abacus to show 10 and the extra ones, and write the other addend). Students use base-10 blocks to trade ten unit blocks for a ten rod and represent numbers like 12 as 10 + 2. Students create equivalent coin combinations (e.g., 12 cents as 1 dime + 2 pennies or 2 nickels + 2 pennies), showing different groupings that result in the same total.

Students are instructed to create 30 "Do the Math!" cards that include problems about number bonds (e.g., "Which number bonds with 5 to make 10?" and "Which number bonds with 10 to make ___?"). The directions tell students to fill in blanks on partially completed cards and to make blank cards with their own numbers, so students generate and solve number-bond problems that involve composing to make 10. The game play requires students to answer these cards during play and correct mistakes, giving repeated practice with those number-bond problems.

Students model and read two-addend number sentences using manipulatives and an abacus (for example, they move 5 beads then 3 beads and read 5+3=8). Students complete worksheets and activities that require writing and solving addition sentences (Animal Addition and Adding on the Abacus) and use counters or number lines to find sums. Students create and record all pairs that make 10 using number bonds, the abacus, and wristbands, then read each pair as a number sentence (for example, "one plus nine equals ten").

Students use counters, plates, and an abacus to model and compare pairs like 3+4 and 4+3, verbally state the turn-around facts, and draw lines matching commutative pairs on the "Turn-Around Facts" worksheet. Students split 10 on the abacus into different two-number combinations (e.g., 4+6 and 3+7) and state the corresponding addition sentences. Students play addition games and complete activities that require finding and confirming equal sums, reinforcing that order of addends does not change the total.

Students are asked to say an addition fact and then state the turn-around fact and answer, practicing that 4 + 3 and 3 + 4 are equivalent (commutative). Students solve missing-addend problems like 4 + ? = 10 using counters, drawings, and an abacus, explicitly making a ten to find the unknown. Students practice recognizing when they are adding or subtracting (counting up vs. counting down) and use strategies (counters, abacus, fingers) to compute sums and differences.

Students use play one-dollar bills as counters to add groups of items on the "Shopping" sheets, including problems with three addends and varied prices. The lesson states, "the process for adding three numbers together is the same as adding two numbers together," which is presented to the student. Students also practice subtraction when giving change in Activity 2 by using a ten-dollar bill and returning one-dollar bills as change.

Students group craft sticks into sets of five and count by 5s then add remaining ones when representing numbers such as 16 and 24, and they are asked to draw and record tally marks for numbers from cards. Students record counts in a tally chart for Skittles and then write totals for each color, answering addition and subtraction questions such as "How many green and purple Skittles did you draw altogether? (7)" and "How many more yellow Skittles are there than purple ones? (4)." Students roll a die 20 times and record tallies, then interpret the resulting counts to answer which numbers occurred most or least often.

Students count and add quantities when they answer questions like "How many fish are there altogether?," "How many red Skittles and yellow Skittles together?," and "How many orange, yellow, and green Skittles did you pick in all?". Students create bar graphs and totals from tally charts and pictographs (e.g., write totals in the "Total" column and color boxes to represent counts), and they combine two or three category counts in several tasks (toy categories, Skittles colors, sea life).

Students practice decomposing numbers into parts of ten through the Number Chants (for example, "6 is 5 and 1" and "10 is 9 and 1" and "10 is 5 and 5"), supporting making tens as a strategy. In Activity 1, students are asked to use manipulatives (counters, abacus, number line) and to describe three different ways to solve a two-addend problem (3 + 5), which prompts use of addition and subtraction strategies. Activity 2 prompts students to identify missing addends and to review the = sign and what 0 does in addition and subtraction, and students create and read their own number sentences aloud.

The lesson explicitly defines the associative property of addition in the Facts and Definitions section and later names it in Activity 2: "Does Order Matter in Addition?" where students reorder groups and confirm the sum remains 10 or 9. The reading activity asks students to identify "turn-around facts" from the book and to say number sentences aloud, which addresses the commutative idea that order of two addends does not change the sum. The "Order and Addition" matching activity has students connect equivalent addition sentences (e.g., reordered addends) and compute sums, giving practice with using order/grouping for addition.

Students identify and practice turn-around (commutative) facts in the Number Chants and the Making 10 activity (e.g., placing 1+9 and 9+1). Students rewrite and regroup sums to make ten (e.g., 9+6 -> 9+1+5 -> 10+5) and use the abacus to trade beads to form 10, explicitly modeling the strategy. Students are prompted in the "Adding 3 Even Higher" activity to look for two-number combinations that make 10 when adding three numbers.

Students are prompted to state turn-around facts (e.g., "Three plus five equals eight" and the turn-around "five plus three equals eight") in the introduction and during activities, explicitly practicing the commutative property. Students use the abacus to trade beads to make 10 (e.g., modeling 9+8 and moving 1 from the 8 to the 9 to make 10, then finding the total) and complete many practice problems that use the making-10 strategy. Students also practice the "two 5s make 10" approach with counters and plates (e.g., decomposing 9+6 into 10+5) and complete worksheets and matching games that reinforce these addition strategies.

Activity 1 asks students whether the order of numbers matters and explicitly states that the order doesn't matter, addressing the commutative idea. The same activity models 4 + 6 + 3 → 10 + 3 and 5 + 2 + 3 → 5 + 5, showing students how to group addends to make ten and use the associative idea as a strategy. Multiple games (Number Toss, Climbing the Path, Party Paper Chains, and First to 10) prompt students to look for sums that make 5 or 10 and to rewrite or combine addends into easier-known sums.

The lesson includes activities where students represent the same total in different groupings (Activity 2 asks students to show $10 in two ways and to show amounts like $11 and $12 using different combinations of bills). The teacher models a making-ten strategy explicitly by saying, "Two fives is ten and then we add one more to get 11," while counting bills aloud. The student pages include addition of three numbers (e.g., 5 + 8 + 6 = 19) and tasks that require creating number sentences and finding sums and differences using manipulatives and an abacus.

Students generate two-addend and three-addend addition sentences for a given sum (e.g., write 5 + 6 = 11 and 2 + 5 + 4 = 11). Students fill the prompt "10 combines with ______ to make the missing number," which directs them to find the complement to 10 (e.g., 10 + 1 = 11). Students use counters and an abacus and are asked to divide 11 counters into three groups to create three addends, practicing regrouping and composing numbers.

Students are prompted to use "turn-around facts" and the "role of zero" while practicing addition and subtraction, and they complete timed flashcard practice and a Math Facts Quiz that includes paired problems like 2+3 and 3+2 and 0+3 and 4-0. The curriculum explicitly lists "Add and subtract within 20, demonstrating fluency for addition and subtraction within 10" as a skill, and students repeatedly solve basic addition and subtraction number sentences during the introduction and practice activities.

Students complete a timed Math Facts Quiz with ten basic addition and subtraction problems (e.g., 1+3 and 3+1 both appear) and are told to "use the tricks that he knows" to find answers. The skills list includes practicing addition and subtraction within 10 and within 20. In the "Rolling With the Time" activity students roll two dice and add the numbers on them to determine times, requiring them to combine two addends in different rolls.

Students flip two number cards and find both the sum and the difference, practicing addition of two addends (Getting Started). Students complete timed addition and subtraction facts to 5 and 10 on the Math Facts Quiz and with flashcards, reinforcing addition/subtraction fluency. Students add the two ends of dominoes to determine which to keep and then add domino totals during the Domino War game, practicing addition of two numbers in context.

Activity 2 explicitly tells students to use "turn-around facts" and other tricks for figuring sums and differences, and the Math Facts Quiz includes paired problems 4+5 and 5+4 showing the same sum. Students are given time to practice addition and subtraction facts via an online game and a timed quiz, reinforcing the use of strategies such as what zero does, adding to 5 and 10, and adding/subtracting 1.

Students repeatedly group and count objects in tens (Activity 3: use 10 baggies or plates to count groups of ten; counting by tens to 100) and trade 10 ones for a ten rod (Activity 1: adding a unit to 99, then exchanging 10 ones for a ten rod and 10 tens for a hundred flat). Students practice counting by tens on the abacus and with dimes, and they reason about how many groups of ten they need to reach 100 (e.g., if they have 4 baggies, how many more to get to 10?).

Students use number bonds and an abacus to find missing addends (e.g., determine 7 to complete 3+7=10) and write addition sentences such as 3+7=10. They extend that work to tens by finding complements to 100 (e.g., 30+70=100, 40+60=100) using ten rods and by reading sentences as 3 tens + 7 tens = 10 tens. Students complete a "Making 100" worksheet filling in blanks for X + ___ = 100, practicing decomposition of numbers into additive pairs.

Students use base-10 blocks and an abacus to add and subtract multiples of ten, physically adding ten-rods or moving bead-rows to form sums such as 10+30, 60+20, 30+20, and 50+40. Students complete activity pages where they roll numbers, write the corresponding multiples of ten (e.g., 20 and 30), draw base-10 representations, and find the sums and differences. Students compare one-digit sums (1+3=4) with tens sums (10+30=40) to see that adding tens works like adding ones and count by tens to find results.

Students practice adding and subtracting multiples of ten in Activity 2 (e.g., 40+20, 30+40, 90-40) and match number sentences to their sums/differences in the Concentration game. The lesson also has students compare 3+3=6 with 30+30=60 and explicitly has them say "3 tens plus 3 tens equals 6 tens," and students are prompted to use base-10 blocks or an abacus to find sums and differences. The 10 More/10 Less activities have students find numbers that are 10 more or 10 less and reason about how the tens digit changes when adding or subtracting 10.

Students draw two number cards and find sums and differences, practicing addition and subtraction with two addends. Students use base-10 blocks to group unit blocks into tens and write number sentences such as "2 tens + 5 ones = 20 + 5 = 25," showing decomposition and recomposition of numbers. In Activity 4, students judge true/false for equations including equivalences (for example, 3+1 = 2+2 and 8-4 = 6-2), encouraging recognition of equal expressions. The unit repeatedly allows students to use manipulatives or mental strategies to compute sums and differences.

Students practice adding multiples of ten by thinking of numbers as tens (e.g., 20 + 30 as 2 tens + 3 tens) and use the abacus and base-10 blocks to find sums in Activity 2. Students complete number-bond tasks with multiples of ten (e.g., filling pairs that add to 60, 80, 50, 30, 70) in Activity 3, which has them compose and decompose tens. The lesson also prompts students to see that adding tens is analogous to adding ones (showing 3+3=6 then 30+30=60).

Students use base-10 blocks and ten rods to combine groups of tens to find sums (for example, finding the sum of 30 and 50 by counting ten rods). Students use an abacus and are asked to move beads in groups of ten to find differences and to begin subtraction with the larger number. In Activity 1 students write addition and subtraction sentences from two multiples of ten and are prompted to think of 3 tens + 6 tens = 9 tens when finding sums. Activity 2 asks students to treat multiples of ten as numbers of tens when deciding whether to add or subtract.

Students practice adding multiples of 10 (10, 20, 40, etc.) to given numbers using place-value mats, base-10 blocks, and an abacus, and they name sums mentally (Activities 1–3). Students complete matching activities that connect number sentences, base-10 block representations, and sums, and they solve two-addend problems such as 15 + 30 and 13 + 60. Students are explicitly reminded that order does not matter and are prompted with "turn-around facts," so they practice adding when the multiple of 10 appears first or second.

Students are asked to use base-10 blocks, an abacus, and mental math to add two-digit numbers and multiples of ten (Introduction: add 56 + 30 using the abacus; Activities: allow use of base-10 blocks or abacus to figure out sums). The lesson repeatedly gives problems that involve adding multiples of 10 (e.g., 20 + 30, 50 + 10, 22 + 40) and prompts students with strategy questions such as "How would you like to solve this problem?" and "How do you know that your answer is correct?". The wrapping up activity asks students to use mental math and then check answers with the abacus, reinforcing use of strategies and place-value reasoning.

Students use base-10 blocks and an abacus to add 35 + 5, exchange 10 ones for a ten rod, and record 35+5=40, showing composing a ten with manipulatives. The lesson explicitly models decomposing a two-digit number (16) into 10 + 6 and rewriting 16 + 4 as 10 + 6 + 4, then uses 6 + 4 = 10 to regroup to 10 + 10 = 20. Matching and "What's Missing?" activities require students to find addends that make the next multiple of ten (e.g., 52 + 8 = 60), practicing counting up to tens and finding missing addends.

Students physically add unit blocks to a ones place and, when they count 11 units, exchange 10 units for a ten rod (Activity 1: 37 + 4 → 41). Students are instructed to use base-10 blocks and an abacus to find sums and told that some problems will require them to "compose 10" (Day 2 Activity 3 and web link). In the Wrapping Up section, students represent problems like 40 + 50 by adding tens and are prompted to describe composing a ten for problems such as 45 + 5.

Students use a place-value mat, base-10 blocks, and an abacus to find sums and are explicitly told to add the ones first and then the tens. Students rewrite horizontal addition sentences vertically, align tens and ones in grids, and solve problems such as 38 + 5, 56 + 10, and other sums involving multiples of 10. Students are prompted to explain how they solved problems and are asked guiding questions about making 10 and what happens to the tens digit when adding 10 or a multiple of 10.

Activity 2 has students cut, solve, and sort number sentences into boxes and explicitly asks them to "point to a pair of turn-around facts" and find additional pairs (e.g., 1+3 and 3+1, 5+3 and 3+5). The answer-key image and sorting pages present multiple examples of commutative pairs (e.g., 5+3 / 3+5, 4+6 / 6+4) for students to identify and place. Activity 1 has students generate and compute sums of three numbers (rolling three dice and writing 1+4+6 = 11) so students practice adding three addends.

Students practice number complements to make 10 in the Intro activity where they draw cards 1–10 and name the number that combines with the drawn card to make 10. Students use place-value strategies with manipulatives in Activity 1 to show and compute problems like 26 + 30, and they complete a worksheet of two-addend problems that pair a two-digit number with a multiple of 10. Students play the online "Facts to Make 100 (Multiples of 10)" game and a wrap-up activity that requires naming the number that adds to a multiple of 10 to make 100.

Students are asked to show cent amounts (8, 10, 14, 17 cents) using pennies, nickels, and dimes and are challenged to show each amount in more than one way. The example explicitly tells students they might show 8 cents using 8 pennies or 1 nickel and 3 pennies, which requires composing sums of coin values (e.g., 5 + 3 = 8).