Function machines
Name: _____________________ Date: __________
Show your thinking with numbers, words, or a drawing.
1. In 5 → Out 13, In 4 → Out 11. Rule: × 2 + 3. What comes out for In 2?
2. In 4 → Out 12, In 9 → Out 22. Rule: × 2 + 4. What comes out for In 8?
3. In 7 → Out 16, In 1 → Out 4. Rule: × 2 + 2. What comes out for In 8?
4. In 7 → Out 19, In 8 → Out 21. Rule: × 2 + 5. What comes out for In 5?
5. In 8 → Out 18, In 9 → Out 20. Rule: × 2 + 2. What comes out for In 4?
Answer key · Function machines
1. 7
The rule is × 2 then + 3.
2 × 2 = 4.
4 + 3 = 7.
2. 20
The rule is × 2 then + 4.
8 × 2 = 16.
16 + 4 = 20.
3. 18
The rule is × 2 then + 2.
8 × 2 = 16.
16 + 2 = 18.
4. 15
The rule is × 2 then + 5.
5 × 2 = 10.
10 + 5 = 15.
5. 10
The rule is × 2 then + 2.
4 × 2 = 8.
8 + 2 = 10.
Try it together
Choose a question from the printable. Use objects or a drawing to show your thinking, then explain your method to someone at home.