# 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.

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.

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.

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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# See You Later Alligator

A Making It Work Guest Blog

I have seen alligators, fish, movable Popsicle sticks, and more as ways to teach the math idea of greater than or less than to young children. Even though these are a good visual tools, to be honest, there are no alligators or even fish in mathematics.

Because many students still fail to understand this concept, here is a different approach which you might want to try. Since all kids know how to connect dots, let’s use that approach.

Suppose we have two numbers 8 and 3. Ask the students, “Which number is greater?” Yes, 8 is greater. Let’s put two dots beside that number.”

Now ask, “Which number is smaller or represents the least amount? Yes, three is smaller. Let’s put one dot beside (in front of) that number.”

Now have the students connect the dots.

It will work every time! When two numbers are equal, put two dots beside each number and connect the dots to make an equal sign.

What makes this method a little different is that the students can visually see which number is greater because it has the most dots beside it; so when reading the number sentence, it is usually read correctly.

This Everyday Learning guest post was written by Scipi, an educator from Kansas who currently teaches math at the local community college. Read more of her easy-to-use math ideas at gofigurewithscipi.blogspot.com.

How are you exploring elementary math concepts today?

# 9 Picks for Kids Who Fear Algebra

Math Phobia can come from many sources. Maybe you were a product of a school that focused on memorizing facts, instead of understanding concepts. If you were like me – I was still counting with my fingers well into my 30s – you didn’t fare too well in that type of math class.

For some kids, their brains are wired to see the world in big pictures… literally. Most classes are taught in a linear way. You learn one idea first before you move on to learning the next idea. Visual-spatial learners, on the other hand, don’t tend to follow that line of thinking. Their approach to math is almost like jumping off a cliff and then wading through a mess to see how everything fits together.

Then, you have the bright kids who find certain subjects easy to learn – it’s just that math isn’t one of them. Since they’re not used to struggling to learn, they avoid it rather than facing the challenge.

Whatever the cause, bad math attitudes and avoidance from younger years can set the stage for endless battles when it comes time for learning algebra – especially if you’re trying to use a textbook like Saxon Math.

Have no fear, we’ve found some great books that will make learning algebra easier – maybe even downright enjoyable!

Alternative Algebra Textbooks

How are you teaching Algebra to your math-phobic kid?

# Alphametic Problem Solving Strategies

 Alphametics are a type of verbal arithmetic brainteaser. They look easy to solve, but they can prove to be a real head scratcher if you just take a trial-and-error approach.

Two basic rules guide solving alphametics.

1. Each letter must be represented by a different digit. If the letter is used more than once, it must be represented by the same digit.
2. Once you substitute digits for all your letters, you must wind up with an accurate addition problem.

Before you start solving these brainteasers, take a minute to remember the Additive Identity and the Commutative Properties of addition. Think about how these properties may be represented in an alphametic puzzle.

For example, the Additive Property – the rule that any number plus zero always equals itself – would look like:

A + B = A

That sure seems easy, until your numbers get bigger and you start to carry groups of ten into your next column.

Let’s see a problem solving strategy in action.

Now that we know we’ll be carrying a group of tens, we know three basic facts about this problem:

1. A + C >= 10
2. B + 1 = D
3. B cannot equal 0 or 9

At this point, we can plug some numbers in to see what might satisfy this equation. We’ll start by brainstorming any set of facts that equal 10, 11, 12, … 17. (We know the sum of the one’s column cannot equal 18, because the only two single digits that equal that sum are 9 and 9. A and C must be different digits.)

If we randomly choose A = 7 and C = 5 we see:

We’ve successfully solved this problem! We could have, however, chosen different values for A and C and still gotten a correct solution. This particulare problem has 18 different answers that work.

Let’s take a look at a harder alphametic problem:

Before we start guessing numbers, let’s analyze the one’s and ten’s column.

B + D = E

B + C = E

Since each letter must be represented by a different digit, the only way both of these statements can be true is if we carry a group of tens into the B + C column. Knowing that means:

C + 1 = D

Next, we look at the hundreds column. The only way A = C is if we carry over to this column, also. We now have a second rule we must remember:

A + 1 = C

At this point, we have enough information to make an educated guess on how to solve this puzzle. We can begin by randomly choosing A=1, C=2, and D=3.

Since B + 3 must be equal to or greater than 10 and E cannot equal 1, 2, or 3 (because those are the digits we’re using for A, C, and D), the only possible answer is that B = 7.

Had we started by making A equal a number other than one, we would still be able to solve the puzzle using the same basic rules.

Do you enjoy these kinds of brainteasers? Get more Alphametic Puzzles for your kids to work on.