Students count and represent numbers 1–5 using concrete objects and base-10 unit blocks (Activities 2 and 4). Students place objects in a two-part number bond and count the total to show part-part-whole relationships (Activity 3). Students solve for a missing part when given the whole and one part (e.g., 4 in the whole circle and 1 in a part circle, so the other part is 3). Students compare two groups of objects and determine which is greater/less and how many more by lining up rods (Activity 5).

Students solve comparison word problems such as "Kate has 5 cookies, Thomas has 3 cookies. Who has more? How many more?" by lining up counters and using an abacus or base-10 blocks to count the difference (Activity 5). Students complete tasks that ask which set is greater and write "how many more" on activity pages, and they fill in the sentence template "_____ is _____ more than _____" after rolling numbers (Activities 5 and 6). Students also model the "one more than" relationship with base-10 blocks and the abacus to show adding one to a quantity (Activity 2).

Students create and solve joining problems using manipulatives and drawings (Activity 8: Fish Stories) where they combine groups (e.g., 6 fish and 4 fish) and find the total. Students use number bonds, dice, and abacus work (Activity 5 and Activity 6) to represent part-part-whole relationships and to produce combinations that make 10. Students complete ‘‘What's Missing?'' equations (e.g., 10 = 6 + ( )) and fill blanks on story-problem pages to represent unknowns and totals using pictures and blanks.

Students are presented with an explicit addition word problem about cookies (need 10, have 5) and are encouraged to use fingers to solve it. Students use manipulatives (abacus, coins, counters) and drawings (activity pages to draw objects and color beads) to represent and count amounts up to 15. Students practice composing amounts with coins (showing 7 cents, 11 cents, making 5 cents two ways, showing 13 cents using 2 nickels and 3 pennies) which requires adding and decomposing within 20.

Students use number bonds with an abacus to write a number 11–20 in the large circle and find the missing addend (e.g., writing 15 and determining 5). Students decompose numbers 11–20 with base-10 blocks and represent amounts with coins, counting up from 10 to make numbers such as 11–20 using manipulatives and drawings on activity pages.

Students use counters to place two quantities side by side, count each group, and answer which group is greater or less. Students are asked to tell how many more are in the greater set than in the lesser set (Activity 4) and to compare pairs of numbers using owl puppets and a number line (Activity 5). Students count real-world quantities in the kitchen and determine which is greater within 20.

Students create and answer "Do the Math!" cards that include number bonds, coin amounts, and comparing numbers (e.g., "Which number bonds with 5 to make 10?" and "The astronaut has a penny and a dime in his pocket. How much money does he have?"). Students sort and fill in cards for categories including before/after, greater than/less than, number bonds, coin amounts, and counting by 2s and 5s. During play, students answer these cards to stay on their space or move back when incorrect, providing repeated practice with these item types.

Students use physical coins and drawings to make and identify amounts within 20 (e.g., make 6, 11, 15, and 16 cents using pennies, nickels, and dimes). Students use an abacus and a laminated number line to count and combine values (modeling addition by moving beads and writing resulting numbers). Students draw coins to represent given monetary amounts and fill in missing numbers in skip-counting sequences, which practices combining quantities within 20.

Students use a laminated number line to count up and back and answer questions such as "What number is 1 more than 5?" and "How many jumps do you make to get from 3 to 6?", practicing movement to the right/left to represent adding and subtracting. In Activity 2, students roll a die, place a counter on a starting number, count up by the die result and count back by the same amount, recording the added and subtracted results on a worksheet (e.g., start 10, roll 3 → 13 and 7). The lesson has students use concrete objects (die, counter, number line) and write resulting numerals within a range that stays well under 20.

Students use objects (pretzels) to represent quantities and physically add items to make two amounts equal (Activity 1), and they compare amounts by identifying which plate has more or none. Students practice adding zero to a set and compare zero to one using concrete objects (Activity 2). Students count and represent numbers with objects up to 10 and are directed to play a counting-to-20 activity online (Activity 3).

Students model and solve addition story problems using objects (counters, pennies) and an abacus (e.g., Ashley has 5 pennies then got 3 more; students count and write 5+3=8). Students create and read addition equations from picture-based tasks (Animal Addition, Adding on the Abacus) and fill blanks in equations (e.g., _ + 2 = _, _ + _ = 7) to represent unknowns. Students combine groups of animals to find totals (five plus seven equals twelve) and answer comparison questions from the read-aloud (Which group has more pandas? How many more?). Students make and record pairs that add to 10 (wristband activity and Showing 10 on the Abacus) using objects and drawings.

Students solve addition word problems using objects and manipulatives: they count play dollar bills to split 10 into equal shares and answer questions like "What if you have two more dollars than I have?" Students use the abacus and counters to model and solve problems such as Ted has 5 cookies and gets 3 more versus Shyan has 3 and gets 5, and they play Marble Math to complete number sentences up to 20. Students use coins and counters to show equal amounts, split tens into two groups, and complete worksheets that compare addition sentences (e.g., coloring pairs that are equal and matching turn-around facts).

Students solve word problems with objects and drawings in Activity 2 ("What's Missing?"), where they make piles of counters, draw pictures, use an abacus, and write equations such as 4+?=10 and problems like 5+?=7, ?+3=5, and 2+?=8. In Activity 4 ("Taking Away") students physically remove objects, use fingers/counters/abacus, and write number sentences such as 10-4=6 and 10-8=2. The Skills list explicitly states "Use addition and subtraction within 20 to solve word problems" and "Understand subtraction as an unknown addend problem," and Day 2 reading includes modeled number sentences such as 12-5=7.

Students use play one-dollar bills as counters to add the costs of multiple items (Activity 1), including adding three or four numbers together and writing the total on the Shopping sheet. Students act as clerk and shopper to find correct change after a purchase, using ten one-dollar bills and recording purchases on a whiteboard (Activity 2), which has them compute 10 − purchase total. The lesson directs students to use objects (play money), drawings or written records on a whiteboard, and counters to represent and solve these problems.

Students create an addition-and-subtraction sticker book with six explicit word problems within 20 (e.g., 3 + 4; 8 - 4; 10 - 3; 2 + 7; 8 - 5; 3 + 4). Students write corresponding number sentences in boxes and model problems using colored dot stickers (placing stickers for addition, and putting an "X" over stickers to show those taken away). The activity also asks students to create word problems from given number sentences and to decorate stickers to represent objects in the problems.

Students use objects and drawings to represent numbers: they lay out craft sticks to show 4, 9, 16 and make groups of five, then copy those arrangements as tally marks. In the Tallying Skittles activity students record counts for each color and answer questions that require combining and comparing counts (e.g., "How many green and purple Skittles did you draw altogether?", "How many more yellow Skittles are there than purple ones?"). Students roll a die and record tallies for 20 rolls, then interpret which numbers occurred most or least, practicing representation and interpretation of quantities.

Students count category amounts on pictographs (e.g., Eagle 5, Bluebird 4, Duck 3) and answer questions that require combining counts, such as "How many birds did the birdwatcher see in all? (17)." Students add survey results to find totals (e.g., "How many people in all responded to the survey? (15)") and create a Skittles pictograph by placing and drawing one picture per candy, representing counts with objects/drawings. Students also compare category sizes (e.g., which type was seen most or least, which day had the most cars) based on the pictograph representations.

Students count and combine categories to find totals (e.g., "How many Skittles would you have if you put all the red ones and yellow ones together?" and "How many games and puzzles do you have altogether?"). Students find differences in comparisons (e.g., "How many more spotted fish than striped fish are there?" and "How many more seahorses than sharks are there?"). Students use concrete and pictorial representations—gluing colored squares to build bars, drawing tally marks, and coloring boxes on bar graphs—to represent and compute quantities.

Activity 2 has students use counters to compare amounts and is explicit that they will use addition or subtraction to answer questions. The "Who Has the Most?" problems require solving word problems such as "Marta has 2 more than Beth (Beth = 8)" and "Jack has 3 fewer than Beth," which ask students to compute unknown quantities within 20. The lesson instructs students to line up and count counters and to create a graph showing the numerical results, providing object- and drawing-based representations of the situations.

The lesson lists "Add and subtract within 20" and "Determine the unknown whole number in an addition or subtraction equation relating three whole numbers" as skills. Activity 1 gives a contextual putting-together word problem (3 + 5) and a follow-up comparing/missing-addend question (goal of 10, how many more?). Activity 2 (Something's Missing) has multiple equations with blanks in different positions (e.g., 5 + ___ = 10, ___ - 3 = 1, 6 - 6 = ___) and instructs students to use counters, abacus, or a number line and to write their own number sentences.

Students solve put-together word problems (e.g., "Hungry Henry puts 3 marshmallows... 3 + 4 + 2") using counters and an abacus to find sums. Students create and record addition sentences with objects (10 counters, sticky-note + and =) and write equations such as 3 + 3 + 4 = 10 on the activity sheet. Students match and calculate equivalent addition expressions (e.g., 4 + 2 + 1 with 2 + 1 + 4) and practice adding to 10 and adding a die roll to 10 (example: 10 + 3 = 13).

Students practice addition facts within 20 using dominoes, counters, and an abacus, and they create and say addition sentences (e.g., "Six plus two equals eight"). They identify addends and sums, use drawings/manipulatives to find sums, and complete worksheets (Making 10, What 5 Makes) that include equations and some fill-in-the-blank unknowns. Students also match addition sentences with their sums in the Addition Concentration activities, representing problems with equations and physical/drawn models.

The Skills section explicitly lists "Add and subtract within 20," and activities ask students to use counters, an abacus, and a whiteboard to find sums. In Activity 5 (Coin Exchange Game) students roll a die, collect pennies, add amounts, and trade up to nickels/dimes to reach 20 cents, which has them add to a target. Activity 1 (Moving on the Path), Activity 3 (Number Toss), and the Party Paper Chains require students to add two or three addends (e.g., labeling chains with addition sentences like 5+5+5=15) and to compare sums during gameplay.

Students represent the number 18 with addition sentences and coin drawings, showing use of addition within 20 and representations with objects/drawings. Students create and solve subtraction sentences using the egg carton, abacus, counters, and a laminated number line to find differences within 20. Students place cut‑out numbers into boxes on "Filling the Boxes," solving subtraction equations with a missing box as the unknown.

Students solve addition and subtraction word problems within 20 in multiple activities (Zoo Animals problems, Candy Shop totals and change, Connect 3 subtraction game). Students use objects and visual tools to represent problems (counters, abacus, laminated number line, bar graph, and picture price tags). Problems include situations of putting together (‘‘altogether'' and three addends), taking apart/taking from (spending money, differences), and comparing (‘‘how many more'' questions).

Students create addition and subtraction number sentences within 20 using selected number cards (e.g., make two 2-addend sums and two subtraction sentences for a given number). Students use objects, drawings, abacus beads, and counters to represent and practice the numbers and fill blanks (for example, '10 combines with ___ to make the missing number'). Students complete comparison prompts by filling in 'greater than' and 'less than' blanks for the missing number on the number-line/activity pages.

The Skills list explicitly states that students will "Add and subtract within 20, demonstrating fluency for addition and subtraction within 10." In Wrapping Up, students practice addition and subtraction facts using flashcards (addition and subtraction to 5) and timed retrieval, sorting facts into known and unknown piles.

Students complete the "Math Facts Quiz 2," which contains ten basic addition and subtraction problems (e.g., 2 - 0, 0 + 4, 5 - 1, 5 + 0) that require computation within 20. The Skills section explicitly lists "Add and subtract within 20, demonstrating fluency for addition and subtraction within 10," and the wrap-up has students practice addition flashcards to 10. In Activity 1, students roll two dice and add the numbers to determine a time, which has them perform small addition with manipulatives (dice).

Students use objects to find totals when shown groups of coins (e.g., 1 nickel and 3 pennies = 8 cents; 1 dime and 4 pennies = 14 cents) and are asked to name those amounts. Students manipulate base-10 unit blocks and ten rods on a place-value mat to build numbers up to 30, add single units to go from 9 to 10 and from 10 to 11, and exchange ten ones for one ten. Students match numbers to pictures of base-10 blocks in the concentration activity and complete money tasks that ask for different ways to make specified cent amounts.

Students physically add a unit block to 99 and trade ten ones for a ten rod to make 100, showing an adding-to situation and using objects and drawings (base-10 blocks and abacus). Students answer questions such as "How many more do you need to get to 100?" and use groups of ten and counting to determine the missing amount. Students compare two-digit numbers (e.g., 57 and 75) using place-value drawings.

Students use objects (abacus, ten rods, base-10 blocks) and number bond sheets to find missing addends such as finding 7 to make 10 when given 3, and they write the equation 3+7=10. Students represent sums with equations and blanks (for example, X + ___ = 100 on the Making 100 sheet) and read number sentences aloud. The activities ask students to use manipulatives and write number sentences to show how tens combine to make larger totals.

Students draw number cards 1–9 and find sums and differences, using the abacus or counters as needed, which has them add and subtract small numbers. Students use base-10 blocks to represent numbers and write number sentences such as 2 tens + 5 ones = 25 and 20 + 5 = 25. Activity 4 has students evaluate addition and subtraction number sentences (e.g., 4+2=7, 9-6=3) and create true/false equations.

Students solve multiple word problems that require adding numbers (e.g., Abby read 20 + 30 pages, Sam had 10 + 50 shells, Joseph counted 30 + 60 cars). Students are prompted to use objects and drawings—base-10 blocks, an abacus, and a place-value mat—to find answers and to cut/glue numbered answers on addition worksheets. One problem asks for a missing addend (how many more coins are needed to make 40 when there are 20), showing use of an unknown in an addition sentence.

Students solve a one-step adding-to word problem (Sarah picked 13 apples, then 6 more) by drawing a picture and using the abacus and base-10 blocks to find the sum 19. Students use drawings and manipulatives (abacus, base-10 blocks, place-value mat) to represent and compute addition problems such as 16+3 and other two-digit plus one-digit sums. Students write and compute addition number sentences in several activities and play a matching game that links addition sentences with their sums.

Students use base-10 blocks and an abacus to model and solve addition problems by composing tens (e.g., representing 35, adding 5, exchanging ten ones for a ten rod, and writing 35+5=40). Students solve and write equations for one-digit and two-digit addition problems that require making 10 (examples: 16+4, 17+3, 18+2) and complete a matching sheet with problems like 32+8 and 28+2, connecting problems to sums. Students find missing addends using boxes (e.g., 52+□=60, □+25=30) and check answers with manipulatives, thus using objects/drawings and equations with a symbol for the unknown.

Students write and solve explicit addition sentences such as 15 + 4 = 19 and other problems with sums under 20 (e.g., 13 + 5, 22 + 3) and place their answers in blanks. Students use manipulatives and representations — abacus, base-10 blocks, place-value mats, and tens/ones grids — to model addition and to rewrite horizontal problems vertically. Students align digits in ones and tens columns and compose a ten when needed, showing use of drawings/grids and equations to represent addition problems.

Students practice adding within 20 by rolling three dice, writing three-number addition sentences (e.g., 1+4+6) and using manipulatives (counters, number line, abacus) or drawings to find sums. Students solve and sort explicit addition and subtraction number sentences (examples include 4+6, 10-5, 5-0) into boxes labeled by their results, reinforcing finding sums and differences. Students also set up and solve a real-world ‘putting together' word problem (kitchen items) and are invited to lay out items or write the problems to illustrate the situation.

Students are asked to show specific cent amounts (8, 10, 14, 17 cents) using pennies, nickels, and dimes and to show each amount in more than one way, which requires composing amounts by combining coin values. The lesson directs students to express length as a whole number of length units by laying multiple copies of a shorter object end to end and to find objects that are 3, 5, and 7 markers long, which has students build lengths by joining repeated units.