Line up the numbers in columns: ones under ones, tens under tens and hundreds under hundreds. Add the ones first, then the tens, then the hundreds.
When a column makes 10 or more, write the ones digit and carry a ten into the next column. Always estimate first. For 386 + 247, round to 400 + 250 = 650, so the answer should be about 650.
Worked example
Work out 386 + 247
- Ones: 6 + 7 = 13, write 3 and carry 1.
- Tens: 8 + 4 + 1 = 13, write 3 and carry 1. Hundreds: 3 + 2 + 1 = 6.
Answer:633
Key words
- column method
- adding digits place by place in columns
- carry
- move a ten or a hundred to the next column
- estimate
- a quick rounded answer to check with
Practise this
New questions every time.
Common Core-referenced: 3.NBT.A.2