Solving Number Puzzles with Symbols: Lesson for Kids

Instructor: Katharine Reilly
In this lesson, you will practice solving simple number puzzles that are expressed using symbols. Number puzzles and symbols can seem scary and complicated, but here's a secret ... they're not! Using symbols and letters instead of numbers is just as easy.

Solving Simple Number Problems

Think way back to when you first learned math. You began by solving equations, or math problems, with an equal sign that often had a box or a blank where you needed to find the missing number. For example, 'Sarah has 5 kittens and her friend Lori has 3 kittens. How many kittens do they have in all?' When you wrote that down, it became:

basic addition

That's easy, together they have 8 kittens! Likewise, here is the same problem but solving for one of the addends (the numbers that are added together), 'Sarah has 5 kittens. Sarah and Lori have a kitten playdate for their 8 kittens. How many kittens did Lori bring to the playdate?' So, written in math terms it is:


So, Lori brought 3 kittens to the party. That's a lot of kittens! Now, here's where the puzzle part comes in. Let's write the same problems using symbols instead of the blanks. A symbol is something that stands for, or represents, something else. For example, if you see a red octagon, you know it stands for 'stop'.

Even with no words, you know this means stop.
blank red stop sign

But, whoever first made up the sign could have picked any symbol they wanted! So, let's pick a symbol for our math problem. Since any symbol will work, let's use stars.


And again:


Okay, one final time. This time, let's use a symbol that is common in math, the letter x.

5 + ~

So, you can use a symbol, or letter, to replace the blank spot in an equation ... or if you ever invite Sarah and Lori over and need to know how many catnip treats to buy!

Sarah and Lori have 8 kittens.
8 Kittens

More Practice

Let's try some more examples using x instead of a blank for the symbol. It is important to know that in every problem, the x is a different number, as it is just taking the place of the blank. When you write problems, you can use any symbol you like, including the first letter of your name!

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