Column addition
I can line up the digits and carry to add big numbers in columns.
For grown-ups: this lesson in words
Years 3 to 6 · Maths
Column addition: I can line up the digits and carry to add big numbers in columns.
Here is 243: 2 hundreds, 4 tens and 3 ones.
Every digit has its own place: hundreds, tens, ones.
Column addition adds one place at a time, starting with the ones.
Picture: Base 10 blocks showing 243: 2 hundreds, 4 tens and 3 ones. It is split into 200, 40 and 3.
Line up the digits: ones under ones, tens under tens, hundreds under hundreds.
Start on the right. Ones: 3 + 5 = 8.
Tens: 4 + 2 = 6.
Hundreds: 2 + 1 = 3. So 243 + 125 = 368.
Picture: 243 plus 125 worked out as a column addition: the answer is 368.
Your turn: Add the ones, then the tens, then the hundreds. What is 312 + 456?
Picture: 312 plus 456 set out as a column addition, with an empty answer row.
Type a number.
Answer
The answer: 768
768. Ones: 2 + 6 = 8. Tens: 1 + 5 = 6. Hundreds: 3 + 4 = 7.
Picture: 312 plus 456 worked out as a column addition: the answer is 768.
Words to know
- column:
- Digits that line up one above the other: ones, tens, hundreds.
- carry:
- Carry, or exchange: move a ten from one column into the next column on the left.
- estimate:
- A sensible guess, made by rounding the numbers first.
- inverse:
- The opposite. Subtraction undoes addition.
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