Double Or Add Multiplication Math Hack

Some kids just can’t remember their basic multiplication facts. They seem to understand the math concept – and given long enough, they can successfully complete a worksheet – but, for whatever reason, they just don’t have fact families past 5 memorized.

If you have a kiddo who is a whiz with addition but struggles with multiplication, try showing them this simple trick that will help speed up multiplying any 2 numbers – no matter the size.

Begin by drawing 3 columns on a sheet of paper. Down the center column, write the number for the multiplication fact family you will be working with. We’re going to practice multiplying by 7, in this example.

In the first row of the left column write “1”. Say, “Any number times itself equals that number. So, what does 7 times 1 equal?” Write the number seven in the right column.

Move your attention to the second row of the left column. Say, “If we double the number one, what number do we get?” Write the number two in that left column spot.

Now say, “When we’re working on completing this chart we have to remember that whatever we do to one side, we have to do to the other side. So, if we doubled the one on the left side, we have to double the 7 on the right side. What number do we get?” Write the number fourteen in the second row of the right column.

Easy Trick to Multiply Any 2 Numbers

For the next row, ask your child to add together 1 plus 2. Write “3” in the left column. Next, say, “If we added 1 and 2 together on the left side, we have to add 7 and 14 together on the right side. What number do we get?”

Keep working your way down the chart. Eventually, your child should notice that you alternate between doubling or adding two numbers together to get the next product answer in the list. Once you finish the chart, go back and check your work with a calculator to make sure the numbers added up correctly.

Easy Trick to Multiply Any 2 Numbers

The cool thing about this trick is that it can work for any multi-digit fact family. This can be really useful when you’re dividing by 2- or 3-digit numbers without a calculator. Just make a quick double-or-add chart along the edge of your paper and viola, solving multiplication facts will no longer be a problem.

Why Does It Work?

The Distributive Property for Multiplication allows us to either multiply one number by another number – OR – to multiply one number with smaller numbers that add up to a larger number. You can see the Double-Or-Add Math Hack in action with larger numbers.

Easy Trick to Multiply Any 2 Numbers

Understanding how the Distributive Property works is pretty important to algebra. But, I’d save the longer explanation for after they’ve memorized their facts. For right now, your 3rd or 4th grader can stick with building their math confidence as they successfully multiply big numbers.


Do you have a math hack for remembering multiplication facts? Share what’s worked for your kids below!







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alessa

alessa

Alessa Giampaolo Keener, M.Ed. works with clients around the world in developing individualized learning plans that value the strengths and weaknesses of the whole child. While her focus has long been on the social-emotional needs of the gifted child, Alessa also works with governmental agencies in helping to meet the educational needs of children in foster care, as well as those involved in the juvenile justice system. Alessa lives in Maryland, where she homeschooled her kids into college. You can email Alessa at alessa.education (at) gmail.com

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