The column method works for any size of number. Line the digits up by place value, then add from the ones column to the left, carrying when a column reaches 10 or more.
Estimate first by rounding each number. For 24 836 + 15 479, estimate 25 000 + 15 000 = 40 000. Then add exactly. If your answer is far from 40 000, check for a mistake in the carrying.
Worked example
Work out 24 836 + 15 479
- Ones 6 + 9 = 15, write 5 carry 1. Tens 3 + 7 + 1 = 11, write 1 carry 1.
- Hundreds 8 + 4 + 1 = 13, write 3 carry 1. Thousands 4 + 5 + 1 = 10, write 0 carry 1. Ten thousands 2 + 1 + 1 = 4.
Answer:40 315
Key words
- column addition
- adding digits place by place
- carry
- move a ten to the next place
- estimate
- a quick rounded answer
Practise this
New questions every time.
Common Core-referenced: 4.NBT.B.4