BlogMath for Kids3 Ways to Multiply Numbers Just Over 100 in 3 Seconds

    3 Ways to Multiply Numbers Just Over 100 in 3 Seconds

    How fast can you calculate 105 X 107?

    Ah! searching for your calculator?

    In part 1 of this series of posts, SplashLearn Wizard will let you in on a cool trick to perform such multiplications mentally! You would not need a calculator at all!

    The answer will unfold in 3 simple steps:

    Step 1:  Subtract 100 from the numbers and write the differences besides the numbers. (Look at the following illustration)

    math multiply 01

    Step 2: Now multiply the differences i.e. 5 x 7 = 35, and write the product down.

    math multiply 02

    Step 3: Add numbers diagonally, i.e. 105 + 7 or 107 + 5 ( sum will be same ). Write the result of addition on the left hand side.

    math multiply 03

    And Voila! we have multiplied two three digit number in a matter of seconds.

    Final Answer:  11,235

    We have explained the procedure in 3 steps, but if you think this can be done mentally.

    SplashLearn: Most Comprehensive Learning Program for PreK-5

    SplashLearn inspires lifelong curiosity with its game-based PreK-5 learning program loved by over 40 million children. With over 4,000 fun games and activities, it’s the perfect balance of learning and play for your little one.

    Try for free

    Try multiplying :

         a. 102 x 103

         b. 109 x 108

    However, there is a catch. This trick works for numbers just over 100 and less than 110.

    In our future posts we will teach you to take it to the next level. Keep coming back to learn more tricks.

    Now go and impress your friends 🙂

    Related Reading: How to Multiply & Divide Fractions: Steps with Visual Models
    Andrew Scholl
    Andrew Scholl is an educational expert with over 15 years of teaching experience in elementary and middle school classrooms. He currently lives in New Jersey with his wife and two daughters.

    Most Popular

    Recent Posts


    Math & ELA | PreK To Grade 5

    Kids see fun.

    You see real learning outcomes.

    Watch your kids fall in love with math & reading through our scientifically designed curriculum.

    Parents, try for freeTeachers, use for free

    Banner Image