Estimating, adding with regrouping
Answers are for parents and teachers.
1
Add 58 + 27 and show where you regroup.
8 + 7 = 15, carry 1. 5 + 2 + 1 = 8. The sum is 85.
2
Estimate 63 + 28 by rounding. Then add exactly. Is your answer close?
60 + 30 = 90. Exact: 63 + 28 = 91. Yes, it is close.
3
Add 84 + 39.
4 + 9 = 13, carry 1. 8 + 3 + 1 = 12 tens. The sum is 123.
4
Add 215 + 387.
5 + 7 = 12, 1 + 8 + 1 = 10, 2 + 3 + 1 = 6. The sum is 602.
5
Karim says 45 + 38 = 73. Check by adding. Is he right?
No. 5 + 8 = 13, carry 1. 4 + 3 + 1 = 8. The sum is 83, not 73.