Input Output Games

Free · 10 rounds · No sign-up

Function Machine Game

Test a number, compare the clues, and crack the secret rule.

Crack 10 machines

Round
1 / 10
Score
0
Streak
0
Capybara math buddy

One clue can fit two rules. Pick a test that tells them apart.

Input3
Secret rule?
Output9

1. Tap a number to get another clue Required to tell the rules apart

2. Choose the rule

How to Play the Function Machine Game

A function machine follows one consistent rule. Two rules may fit the first input-output pair. Send a new number through the machine, compare what each rule predicts, and choose the rule supported by every clue.

What students practice

Compare Rules includes simple addition, subtraction, multiplication, and division so one clue can support two ideas. Multiply & Divide ranges from ×2 to ×10 and exact division. Two Steps combines operations in a fixed order. Suggested tests keep outputs non-negative.

A useful strategy

  1. Find two rules that could explain the first pair.
  2. Choose a test number that makes those rules predict different outputs.
  3. Check the winning rule against every clue before choosing.

This game is designed for children who already recognize the displayed arithmetic symbols, roughly ages 7–11 as a guide. For a more direct start, apply a visible rule in Input Output Tables.