Every algebra problem hides a number somewhere. Learn to spot the hidden number, keep an equation balanced, and crack the rule behind a pattern.
Sometimes a math sentence is missing a piece. We know almost everything — except one number. We can draw a box where that missing number goes:
What number goes in the box so the sentence is true? You probably said 4 — because 3 + 4 = 7. That hidden number is the whole idea behind algebra.
A box — or a letter like x or n — is just a stand-in for a number we haven't figured out yet. We call it a variable. Your job is to discover what it really is.
So these three all mean exactly the same thing:
The = sign means "the same as." A good way to picture it is a balance scale: whatever sits on the left weighs exactly the same as whatever sits on the right. The cup 🥤 hides the mystery number.
Try it below. How many blocks are hidden inside the cup so the scale balances? Type your guess and watch what happens.
When both pans weigh the same, the scale sits level. The cup's hidden number is whatever makes the two sides match — so balancing the scale is the same as solving for the mystery number.
A function machine takes a number in, follows a secret rule, and sends a new number out. Feed it some numbers, watch what comes out, and see if you can figure out the rule.
Feed in a number:
What's the secret rule?
Patterns are function machines in disguise. Look at the jump from one number to the next — that jump is the rule.
Each step adds 2, so the mystery number is 8 + 2 = 10. Once you know the rule, you can keep the pattern going forever.
How do you get from the first to the second? Did it grow or shrink, and by how much?
Try the same jump on the next pair. If it fits every time, you've found the rule.
Apply your rule one more time to find the mystery number at the end.
Solve each problem to find the mystery number. Type your answer and press Check. You earn a point for every one you get on the first try — finish all eight to see your score.