Equation puzzle · 10-question rounds · three levels

Missing Number Calculator Game

Play a missing number calculator game online. Find the value that completes addition, subtraction, multiplication and division equations with keyboard or touch input.

? Find the unknown10-question rounds3 difficulty levels⌨ Enter to submit

Find the missing number

Complete each equation by working backward. Ten questions make one round.

Browser-based practice
Question1/10
Score0
Streak0
Round10 questions
What number replaces ?
? + 4 = 9

Advertisement

What Is a Missing Number Game?

A missing number game presents an equation with one value replaced by a question mark. Instead of simply calculating from left to right, you work backward to determine the unknown value. For example, in “? + 7 = 19,” the missing number is 12 because 12 + 7 = 19. This small change makes the exercise useful for understanding inverse operations and the basic idea behind solving equations.

Three Difficulty Levels

Easy mode uses addition and subtraction with smaller numbers. Medium mode adds multiplication and larger values. Hard mode can include division questions, with the numbers generated so that the intended missing value is a whole number. Each round contains ten questions and shows score and streak, making the game short enough for a quick practice session while still providing a useful result at the end.

Learning to Work Backward

To solve a missing addend, subtract the known addend from the total. To solve a missing subtraction value, think about which number makes the equation true. For multiplication, divide the product by the known factor. For division, use the relationship between dividend, divisor and quotient. These patterns are the same ideas used later in algebra, but the game keeps the presentation simple and calculator-like.

Keyboard and Touch Controls

Type the missing value in the answer box and press Enter, or use the large onscreen number buttons. The game immediately tells you whether the answer is correct, then moves to the next equation. At the end of ten questions, the result card shows the number correct, accuracy and score. You can restart the same difficulty or choose a harder level for another round.

Frequently Asked Questions

What operations appear in the game?

Depending on difficulty, the game uses addition, subtraction, multiplication and division.

How long is one round?

One round contains 10 equations.

Are division answers whole numbers?

Yes. Division questions are generated with a whole-number missing value.