Math Teaching Tools


Magic Decoder Ring For Solving Word Problems


Magic Decoder Ring in pdf version


The world of word problems is a difficult one to live in for many math students. Many math students todd up their hands in disgust over having to do word problems. They simply see them as impossible, so they see no reason to even attempt them. When I learned how to do them as a teenager, I saw them as fun because my teacher introduced this code for figuring out how to get an equation out of the sentences in the word problems. The word problems just didn't seem as hard when I looked at it this way.

I began each word problem section in my math classes with a whole class participation of coming up with ideas for how to fill in the chart. Everyone came up with ideas for different ways to say addition, subtraction, multiplication, division and the equals sign. Then we took that information and used it to decode a simple word problem. The students started brightening up and smiling because suddenly word problems didn't seem so hard anymore. I saw students using their notes from that day in class for many weeks.

Part of my goal as a math teacher is to make math fun. Some people think this is impossible, but since I learned how to add and subtract by playing a game of cards, I do believe it is possible. This magic decoder ring method of teaching word problems has made word problems easier for many students, so I continue to use it. Give it a try and see if it helps.

Word Problem:Mary has ten apples. She sold three of them. How many are left over?

Mary started out with ten, so we know we have a 10 in the problem. We're looking for how many are left over, so we are subtracting the number she sold, which is three. So our problem looks like this:

10 - 3 = ?

I use a question mark here because not all people are using letters for the question mark yet. The problem could also be written as:

10 - 3 = x

Word Problem: Sally has four more crayons than Billy. Billy has two crayons. How many crayons does Sally have?

We know we are dealing with the numbers four and two. We have a more than used, so we are going to use addition. This problem can be set up in many ways, but we will focus on this one to show how to use the chart. The problem looks like this:

2 + 4 = ?

Or in the world of algebra, the problem looks like this:

2 + 4 = x

The magic decoder ring is listed below or as a pdf file listed at the top of this page. Try it and see if you like it. But most of all, have fun with math! Really, it's not as hard as it looks.



Magic Decoder Ring
+ - X / =
Sum Difference Product Quotient Is
Add Minus Twice Divided By Is Equal To
More Than Subtract Three Times Remainder The Same As
Total Less Than Times Fractions
All Left Over Of (next to a percentage or fraction)
Take Away


Home Page last updated 04/21/08