Quick Methods for Multiplication

This video tutorial from TechMath demonstrates quick methods for multiplying numbers by 5, 25, and 125. The instructor explains the logic behind these methods, showing how to divide and multiply to achieve results instantly. The video includes examples and practice problems, helping viewers understand and apply these techniques effectively.

What is the first step in the quick method for multiplying a number by 5?

• Subtract 2

• Add 5

• Divide by 2

• Multiply by 10

When multiplying an odd number by 5, what should you do with the remainder after division by 2?

• Multiply it by 5 and add to the result

• Add it to the result

• Multiply it by 10

• Ignore it

What is the equivalent operation for multiplying by 25?

• Multiply by 5 and add 25

• Divide by 4 and multiply by 100

• Divide by 2 and multiply by 50

• Multiply by 10 and divide by 2

How do you handle remainders when multiplying by 25?

• Multiply the remainder by 25 and add to the result

• Multiply the remainder by 10

• Ignore the remainder

• Add the remainder directly to the result

What is the first step in the quick method for multiplying a number by 125?

• Multiply by 125

• Multiply by 8

• Divide by 5

• Divide by 8

When multiplying by 125, what do you do after dividing by 8?

• Add 125

• Multiply by 1,000

• Subtract 8

• Multiply by 100

What is the result of 24 multiplied by 5 using the quick method?

• 120

• 130

• 140

• 150

Using the quick method, what is 18 multiplied by 25?

• 450

• 550

• 400

• 500

What is the result of 31 multiplied by 25 using the quick method?

• 775

• 700

• 725

• 750

Using the quick method, what is 138 multiplied by 125?

• 17,750

• 17,500

• 17,250

• 17,000