A comprehensive multi-grade arithmetic practice unit featuring addition and subtraction worksheets with spacious student workspaces, tailored for first and second grade learners.
Strategies: Place value decomposition, regrouping, column work
Problem 19 Ans: 37
24 + 13 = 37
No regrouping: \( 20+10=30 \), \( 4+3=7 \)
Problem 20 Ans: 57
35 + 22 = 57
No regrouping: \( 30+20=50 \), \( 5+2=7 \)
Problem 21 Ans: 65
47 + 18 = 65
Regroup: \( 7+8=15 \); \( 40+10+15=65 \)
Problem 22 Ans: 88
52 + 36 = 88
No regrouping: \( 50+30=80 \), \( 2+6=8 \)
Problem 23 Ans: 92
68 + 24 = 92
Regroup: \( 8+4=12 \); \( 60+20+12=92 \)
Problem 24 Ans: 82
43 + 39 = 82
Regroup: \( 3+9=12 \); \( 40+30+12=82 \)
Regrouping Diagnostic Notes for Set 4
When reviewing Problems 21, 23, and 24, confirm students record the regrouped ten in the tens column rather than writing both digits in the ones place (e.g., writing 515 for 47 + 18).
Addition Builders • Teacher Resource Page 2 of 2
Problem 16 Ans: 7
15 - 8 = 7
Think-addition: \( 8 + 7 = 15 \)
Problem 17 Ans: 5
13 - 8 = 5
Count up: 8 to 10 (2) + 3 = 5
Problem 18 Ans: 7
16 - 9 = 7
Think: \( 16 - 10 + 1 = 7 \)
4
Set 4: Two-Digit Subtraction to 100
Strategies: Place value decomposition, unbundling tens
Problem 19 Ans: 23
38 - 15 = 23
No regrouping: \( 30-10=20 \), \( 8-5=3 \)
Problem 20 Ans: 35
59 - 24 = 35
No regrouping: \( 50-20=30 \), \( 9-4=5 \)
Problem 21 Ans: 27
45 - 18 = 27
Regroup: \( 15-8=7 \); \( 30-10=20 \)
Problem 22 Ans: 27
62 - 35 = 27
Regroup: \( 12-5=7 \); \( 50-30=20 \)
Problem 23 Ans: 33
76 - 43 = 33
No regrouping: \( 70-40=30 \), \( 6-3=3 \)
Problem 24 Ans: 36
83 - 47 = 36
Regroup: \( 13-7=6 \); \( 70-40=30 \)
Regrouping Diagnostic Notes for Set 4
On Problems 21, 22, and 24, confirm students recognize when decomposition is required. Check for the common error of flipping digits (e.g. subtracting \( 8 - 5 = 3 \) in \( 45 - 18 \) yielding 33 instead of regrouping to 27).
Subtraction Builders • Teacher Resource Page 2 of 2
