Multiplication of whole numbers
Multiplication of whole numbers
The product of two whole numbers, m and n is:
m x n=m+m+...+m (n times)
This is just a shorthand for saying, "Add
m to itself n times."
7 x 5 = 7+7+7+7+7=35, but you only write 7 x 5 = 35
Properties of multiplication
1.
Associative: For any three whole numbers a, b and c:
ax(bxc) = (axb)xc
Example 1: Example 2:
(5 x 7) x 2 = 35 x 2 = 70 (4 x 9) x 3 = 36 x 3 = 108
5 x ( 7 x 2) = 5 x 14 = 70 4 x ( 9 x 3) = 4 x 27 = 108
2.
Commutative: For any two whole numbers a and b:
a x b = b x a
12 x 7 = 7 x 12 = 84
24 x 19 = 19 x 24 = 216
