CALCULATING • EXPANDED COLUMN ADDITION 85
When we add together
the 8 and 5, we’re
actually adding 80 and 50.
The answer is 130. On a new
line, write 1 in the hundreds
column, 3 in the tens column
and zero in the ones column.
Add the tens
together
385
157
12
130
H T O
Now we have added the
digits in the bottom row
to the digits in the top row,
we add the three lines in our
answer together:
12 + 130 + 400 = 542
So, 385 + 157 = 542
Next, we’re going to add
the hundreds together.
We add 100 and 300 to give
- On a new line, write 4 in
the hundreds column, 0 in the
tens column, and 0 in the
ones column.
Add the hundreds
together
Answers on page 319
TRY IT OUT
Add it up
Now you have learned this useful
method for adding difficult
numbers, why don't you give
these calculations a go?
385 + 157 = 542
7256 + 4715 =?
948 + 642 =?
547 + 276 =?
Add the three
lines in the
answer together
385
157
12
130
400
385
157
12
130
400
542
H T O
H T O
Expanded column addition
is just like partitioning – we
break tricky numbers into
ones, tens, and hundreds.
084_085_Expanded_column_addition.indd 85 29/02/2016 18:02