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Multiplying by 9’s

Did you know that when you multiply a 9 by another single digit that the digits of the product will add up to 9? This an easy way to help you remember the multiples of 9 and is helpful in checking your answer.

 

Let’s take a look:

2 \times 9 = 18

Notice that the 1 and the 8 in the 18 add up to 9!

Here are a couple more…

9 \times 5 = 54 \:\:\Rightarrow 5 + 4 = 9

8 \times 9 = 72 \:\:\Rightarrow 7 + 2 = 9

Now you try:

9 x 3 =

6 x 9 =

9 x 7 =