Mastering UIL Number Sense Multiplication Short-cuts

What is the first step in multiplying 11 by 32 mentally?

• Write down the number 3

• Add the digits 3 and 2

• Write down the number 2

• Multiply 3 by 2

When multiplying by 11, what do you do after writing down the last digit?

• Divide the digits

• Multiply the digits

• Add the digits

• Subtract the digits

What is the technique called when multiplying by 12?

• Double and divide

• Double and add back

• Half and add back

• Double and subtract

In the 'double and add back' technique, what is the result of doubling 2 and 3 in 32 times 12?

• 2 and 3

• 4 and 6

• 6 and 8

• 4 and 5

What is the easier method for multiplying by 15 if the number is even?

• Half and add back

• Double and subtract

• Double and add back

• Double and half

What is half of 32 in the 'double and half' technique?

• 32

• 8

• 16

• 4

When multiplying by 25, what do you do with the number you are multiplying?

• Multiply by 4

• Divide by 4

• Subtract 4

• Add 4

What is the result of dividing 32 by 4 when multiplying by 25?

• 7

• 9

• 6

• 8

What is the first step in multiplying 29 by 11?

• Write down the number 9

• Add the digits 2 and 9

• Write down the number 2

• Multiply 2 by 9

When multiplying 29 by 25, what do you do with the remainder after dividing by 4?

• Add 50

• Add 25

• Add 100

• Add 75