Addition and Subtraction
Line the digits up by place value, work from right to left, and carry or borrow when a column overflows or underflows.
The column method is the standard written way to add or subtract large numbers. You write one number above the other, making sure the ones line up with the ones, the tens with the tens, and so on.
For addition, if a column totals 10 or more, write the ones digit and carry the tens digit into the next column. For subtraction, if the top digit is too small, borrow 10 from the column to its left.
Use the diagram below to step through the column method. Choose addition or subtraction, enter two numbers, and watch each column being calculated.
Watch it work
Question: Calculate .
Step 1 (ones): . Write 4, carry 1.
Step 2 (tens): . Write 3, carry 1.
Step 3 (hundreds): . Write 6.
Step 4 (thousands): . Write 5.
Answer: .
Have a go
Q1. Calculate .
Ones: , write 6 carry 1.
Tens: .
Hundreds: , write 3 carry 1.
Thousands: .
Q2. Calculate .
Ones: . Cannot do it, so borrow.
But tens column is 0, so borrow across from hundreds, then tens.
.
Tens: after lending, this was 9 (we borrowed through). .
Hundreds: (originally 0, borrowed from thousands giving 10, then lent 1 to tens giving 9).
Thousands: (originally 7, lent 1).
Q3. A school has 1,247 pupils. 589 of them walk to school. How many do not walk?
. Work through the column method with borrowing. Ones: , borrow to get . Tens: , borrow to get . Hundreds: , borrow to get . Thousands: .
pupils do not walk.