Speed Math for Kids Achieve Their Full Potential

Try these   problems    in  your    head:

a)  

b)  

c)  

For a)  you simply  add 300 and subtract    3:

531 +   300 is  831,    minus   3   is  828

For b)  you add 200,    then    add 50, and subtract    1:

333 +   200 is  533,    plus    50  is  583,    minus   1   is  582

For c)  you add 400 and subtract    12:

4,537   plus    400 is  4,937,  minus   12  is  4,925

Adding from left to right

For most additions, if you are adding mentally, you should add from left to right instead of from right to
left as you are taught in school.
How would you add these numbers in your head?

I would add 3,000, then subtract 100 to add 2,900. Then I would add 40 and subtract 2 to add 38.
To add 2,900 you would say, ‘Eight thousand and sixty-four,’ then add 40 and subtract 2 to get ‘Eight
thousand, one hundred and two.’
This strategy makes it easy to keep track of your calculation and hold the numbers in your head.

Order of addition

Let’s say we have to add the following numbers:

The easy way to add the numbers would be to add:
6 + 4 = 10, plus 8 = 18
Most people would find that easier than 6 + 8 + 4 = 18.
So, an easy rule is, when adding a column of numbers, add pairs of digits to make tens first if you
can, and then add the other digits.
You can also add a digit to make up the next multiple of 10. That is, if you have reached, say, 27 in
your addition, and the next two numbers to add are 8 and 3, add the 3 before the 8 to make 30, and then
add 8 to make 38. Using our methods of multiplication will help you to remember the combinations of
numbers that add to 10, and this should become automatic.
This also applies if you had to solve a problem such as 26 + 32 + 14. We can see that the units digits
from 26 and 14 (6 and 4) add to 10, so it is easy to add 26 and 14. I would add 26 plus 10 to make 36,
plus 4 makes 40, and then add the 32 for an answer of 72. This is an easy calculation compared with
adding the numbers in the order they are written.

Breakdown of numbers

You also need to know how numbers are made up. Twelve is not only 10 plus 2 but also 8 plus 4, 6 plus
6, 7 plus 5, 9 plus 3 and 11 plus 1. It is important that you can break up all numbers from 1 to 10 into