Magical Multiplication

Created By: Kristin GenungMath 105

Learning To Multiply:

A FEW MYSTIFYING TIPS

• 0 x 1 = 0• 0 x 2 = 0• 0 x 3 = 0

It’s as simple as that!!

1 x 4 = 41 x 5 = 51 x 6 = 6

1’s

2 times any number is that number doubled

2 x 3 = 6

=2 2 2 6

+ +

2’s

2’s

Please, Please, Bring on the 3’s…

3’s

4’s

4’s

4 x 1 = 4 ( 1 doubled is 2 and 2 doubled is 4 )4 x 2 = 8 ( 2 doubled is 4 and 4 doubled is 8 )4 x 3 = 12 ( 3 doubled is 6 and 6 doubled is 12 )

If you are multiplying by an odd number..

Cut the number you are multiplying by in half then drop the decimal

5 x 3 = 15 ( half of 3 is 1.5, then drop decimal)5 x 7 = 35 ( half of 7 is 3.5, then drop the decimal)5 x 9 = 45 ( half of 9 is 4.5, then drop the decimal)

If it is an even number…

- Cut the number in half and add a 0

5

6’s

Take the number your multiplying by and divide it in half.

Then multiply that number by ten.

Then add the original number you are multiplying by.

6 x 6 = 36 Half of 6 = 3 multiplied by 10 equals 30 then add 6 and you get 36.

6 x 7 = 42 Half of 7 is 3.5 multiplied by 10 equals 35 then add 7 and you get 42.

6 x 8 = 48Half of 8 is 4 multiplied by 10 equals 40 then add 8 and you get 48.

7’s

No need to be slick there isn’t a trick…

7 x 7 = 497 x 8 = 56

8’s

Once again use the tricks..

8 x 8 = 64

9’s

Subtract 1 from the number you are multiplying by then add a second number that adds up to nine..

• 9 x 7 = ( 7 – 1 = 6, 6 +3 = 9 so the answer is 63)• 9 x 8 = ( 8 – 1 = 7, 7 +2 = 9 so the answer is 72)• 9 x 9 = ( 9 – 1 = 8, 8 +1 = 9 so the answer is 81)

10’s

Just add a 0 to the number you are multiplying by

• 10 x 2 = 20 • 10 x 3 = 30• 10 x 4 = 40

11’s

Any number 1-10 multiplied by 11 is just duplicated.

11 x 3 = 33(3 is multiplied by 11 so you just duplicate 3 side by side)

11 x 4 = 4411 x 5 = 55

12 were done…Now let’s have fun…

Use your tricks 1-11 …

And 12 x 12 = 144