Fast Multiplication Tricks: Multiply Like a Pro!

TLDRLearn a variety of fast multiplication tricks, including multiplying by 11 and teen numbers, as well as multiplying bigger two-digit numbers. Follow step-by-step examples and master the art of quick mental calculations!

Key insights

🔢Multiplying by 11: You can easily multiply a number by 11 by adding the digits of the number and placing the sum between them.

🔢Multiplying by teen numbers: To multiply a number by a teen number, multiply the units digit of the teen number by the given number, and add a 0 to the result. Then, multiply the tens digit of the teen number by the given number and add the two results.

🔢Multiplying bigger two-digit numbers: Multiply the units digits of both numbers, then cross-multiply the units digit of the first number with the tens digit of the second number and the tens digit of the first number with the units digit of the second number. Add the two cross-multiplication results and the product of the units digits to get the final answer.

Q&A

How do I multiply a number by 11?

To multiply a number by 11, add the digits of the number and place the sum between them.

How do I multiply a number by a teen number?

Multiply the units digit of the teen number by the given number, add a 0 to the result, then multiply the tens digit of the teen number by the given number and add the two results.

What is the trick to multiplying bigger two-digit numbers?

Multiply the units digits of both numbers, cross-multiply the units digit of the first number with the tens digit of the second number and the tens digit of the first number with the units digit of the second number, and add the two cross-multiplication results and the product of the units digits.

Are these tricks applicable to any number?

Yes, these tricks are applicable to any numbers within the specified range.

Are there any other tricks for mental calculations?

Yes, there are various other tricks for mental calculations, including squaring and working with percentages.

Timestamped Summary

00:00In this video, you will learn a variety of fast multiplication tricks.

00:07Multiplying by 11: Add the digits of the number and place the sum between them.

01:31Multiplying by teen numbers: Multiply the units digit of the teen number by the given number, add a 0 to the result, then multiply the tens digit of the teen number by the given number and add the two results.

02:29Multiplying bigger two-digit numbers: Multiply the units digits of both numbers, cross-multiply the units digit of the first number with the tens digit of the second number and the tens digit of the first number with the units digit of the second number, and add the two cross-multiplication results and the product of the units digits.

05:54Wrap up and encourage viewers to try these tricks and explore other mental calculation techniques.