How_To_Be_Good_At_Math

86 CALCULATING •^ COLUMN ADDITION

Shopkeeper’s addition

Now we're going to look at another method of column

addition. This is quicker than expanded column addition

(pages 84-85) because instead of writing ones, tens, and

hundreds on separate lines, we put them all on one line.

Next, we add 9 tens to 6 tens.

The answer is 15 tens. Add on the

1 ten we carried over from the ones

addition to make 16 tens. Write the 6

in the tens column and carry the 1 to

the hundreds column.

Let’s use column addition to add

2795 and 4368.

Start by writing both numbers on a

place-value grid, with the larger

number above the smaller number. If

you need to, label the columns.

Now we’re going to add each

number in the bottom row to the

number that sits above it in the top

row, starting with the ones.

First, add 5 to 8. The answer is

13. Write the 3 in the ones
    column. The 1 stands for 1 ten, so we
    carry it over into the tens column to
    add on later.

Start by adding

the ones

Carry the 1 from

13 into the tens

column to add on

at the next step

Th H T O Place the larger

number above

the smaller one

Th H T O

Th H T O

Add the carried

1 ten to 15 tens,

to make 16 tens

Th H T O

4368 + 2795 =?

2795

4368

• 2795

4368

• 2795

4368

3

1

• 2795

4368

63

11

Once you understand

how to do column

addition, you can use

it for any addition

calculation involving

large numbers.

086_087_Column_addition.indd 86 29/02/2016 18:02