Multiplication Tips

Multiplying by 0:

The answer is always zero.

Example: 0x3 =0    0x5=0 

Multiplying by 1:

The answer is always the other number that is not 1.

Example: 1x6=6     10x1=10    500x1=500

Multiplying by 2:

Look at the other number that's not 2 and double it!

Example:
2x4 =  (double 4; 4+4)     2x4=8

2x8 = (double 8; 8+8)       2x8=16

2x12 = (double 12; 12+12) 2x12=24


Multiplying by 4:

Double Doubles! Take 4 and split it in half. Multiply each number by 2 and then double that answer.

Example:

4x8 =

2x8=16
2x8=16
then add 16+16
= 32

4x7 =

2x7=14
2x7=14
then add 14+14
= 28

4x15=

2x15=30
2x15=30
30+30
=60

Multiplying by 10:

Same rule as multiplying by 1. Look at the number that's not 10 and multiply it by 1 and then add on a zero OR count up by tens.

Example: 6x10=  (6x1=6, then add on a zero) = 60

8x10 = (8x1=8, then add on a zero)=80