When the ones add up to 10 or more, we regroup: trade 10 ones for 1 ten.
Look at the ones. When they make 10 or more, circle them and trade for a ten.
28 + 35
Regroup 10 ones as 1 ten
47 + 26
Regroup 10 ones as 1 ten
Add the ones. If you get 10 or more, regroup. Then add the tens.
28 + 35 =
47 + 26 =
39 + 44 =
58 + 27 =
Look at the ones digits. Will you need to regroup? Write yes or no before solving.
23 + 45: Regroup? ______
28 + 35: Regroup? ______
41 + 56: Regroup? ______
39 + 44: Regroup? ______
Number Talk — Explain WITHOUT calculating.
Which sum is bigger?
28 + 35 or 28 + 45
My thinking:
Which sum is bigger?
47 + 26 or 37 + 26
My thinking:
Challenge — Show two different ways to solve. Try base-10 blocks in your head AND column addition.
38 + 46 =
Strategy 1:
Strategy 2:
57 + 35 =
Strategy 1:
Strategy 2: