Use the 10 times table to solve the 9 times table
Multiply by 10, then subtract one group of the number you are multiplying.
Take 9 × 7. Ten groups of 7 make 70. You only need nine groups, so remove one group of 7: 70 − 7 = 63. This gives you every answer in the 9 times table without treating each one as a separate fact.
Use ten easy groups, then remove the extra one
Treat 7 as one complete group. Ten groups make 70. Remove the single orange group of 7 to leave nine groups worth 63.
Think of 7 as one complete group. Each tile now stands for all 7.
Ten groups of 7 are easy to calculate: 7 tens are 70.
You only need nine groups, so take away the orange group of 7.
How to calculate 9 × 7 in your head
Use the easier 10 times table, then remove one group of 7.
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Find ten groups of 7
10 × 7 = 70
Multiplying by 10 gives you one group more than the question asks for.
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Remove one group of 7
70 − 7 = 63
Ten groups minus one group leaves nine groups.
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State the original answer
9 × 7 = 63
You now have exactly nine groups of 7.
Use the same two steps for every 9 times table fact
Multiply the other number by 10, then subtract that same number once.
9 × 4
40 − 4= 36
9 × 6
60 − 6= 54
9 × 8
80 − 8= 72
The method also works beyond the times table
The other number can be larger than 12. Multiply it by 10, then subtract it once.
Make sure you remove one whole group
The amount you subtract is the other number in the multiplication.
For 9 × 7, subtract 7
Start with 10 × 7 = 70, then calculate 70 − 7.
For 9 × 24, subtract 24
Start with 10 × 24 = 240, then calculate 240 − 24.
Now try 9 × 12
9 × 12 = ?
Find 10 × 12, then remove one group of 12.
Show the answer Hide the answer
Ten groups of 12 make 120. Remove one group of 12: 120 − 12 = 108.
Use it when you see nine equal groups
Counting ten groups and removing one can be quicker than adding nine groups separately.
Calculate nine equal prices
Nine tickets at $7 each cost 10 × $7 − $7 = $63.
Count nine full boxes
Nine boxes with 24 items each contain 10 × 24 − 24 = 216 items.
Use the method while you play
For every question, first say the matching 10 times table fact. Then subtract one group to find the 9 times table answer.
Questions about multiplying by 9
Why do I subtract the other number?
Multiplying by 10 creates ten equal groups. The question asks for nine groups, so you remove one complete group. That group contains the other number.
Does this work when 9 is written second?
Yes. Multiplication works in either order, so 7 × 9 and 9 × 7 both equal 63. You can still calculate 10 × 7 − 7.
Can I use the same idea for multiplying by 99?
Yes. One hundred groups minus one group leaves 99 groups. For 99 × 7, calculate 100 × 7 − 7 = 693.