Arithmetic Grade Five

Lesson Forty-one: Multiplication Review


Multiples

Normally we count by ones like this: 1, 2, 3, 4, 5, 6, 7, 8, 9, etc.

But, we can also count by other numbers. For instance, we can count by twos like this: 2, 4, 6, 8, 10, 12, 14, 16, 18, etc. The number in this list are the first nine multiples of two.

We could also count by threes like this: 3, 6, 9, 12, 15, 18, 21, etc. This list contains the first seven multiples of three

In each case we could go on as long as we like.

When we count by a number we start with that number and then keep adding that number. Study this table to see how counting by three works:

NUMBERADDITION PROBLEMMULTIPLICATION PROBLEM
333x1
63+33x2
93+3+33x3
123+3+3+33x4
153+3+3+3+33x5
183+3+3+3+3+33x6
213+3+3+3+3+3+33x7
243+3+3+3+3+3+3+33x8
273+3+3+3+3+3+3+3+33x9

Here are the first nine multiples of four: 4, 8, 12, 16, 20, 24, 28, 32, 36.

Here are the first nine multiples of five: 5, 10, 15, 20, 25, 30, 35, 40, 45.

Continue to next page of lesson