Column addition with regrouping
Name: _____________________ Date: __________
Show your thinking with numbers, words, or a drawing.
1. 78 + 18 = ?
2. 28 + 44 = ?
3. 79 + 14 = ?
4. 28 + 14 = ?
5. 16 + 38 = ?
Answer key ยท Column addition with regrouping
1. 96
Line up the digits: ones under ones, tens under tens. Add from the ones.
Ones: 8 + 8 = 16, write 6, carry 1. Tens: 7 + 1 + 1 = 9.
78 + 18 = 96.
2. 72
Line up the digits: ones under ones, tens under tens. Add from the ones.
Ones: 8 + 4 = 12, write 2, carry 1. Tens: 2 + 4 + 1 = 7.
28 + 44 = 72.
3. 93
Line up the digits: ones under ones, tens under tens. Add from the ones.
Ones: 9 + 4 = 13, write 3, carry 1. Tens: 7 + 1 + 1 = 9.
79 + 14 = 93.
4. 42
Line up the digits: ones under ones, tens under tens. Add from the ones.
Ones: 8 + 4 = 12, write 2, carry 1. Tens: 2 + 1 + 1 = 4.
28 + 14 = 42.
5. 54
Line up the digits: ones under ones, tens under tens. Add from the ones.
Ones: 6 + 8 = 14, write 4, carry 1. Tens: 1 + 3 + 1 = 5.
16 + 38 = 54.
Try it together
Find 15 buttons or blocks. Make two groups, then move some to make a group of ten. Explain what is left.