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Math Grade 2-3 Answer Key

Math: Function Tables Input and Output

Find the rule and complete the table

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Math: Function Tables Input and Output

Find the rule and complete the table

Math - Grade 2-3

Instructions: Read each function table problem carefully. Use the rule to find the missing numbers. Show your work in the space provided.
  1. 1

    Rule: Add 2. If the input is 5, what is the output?

    Start with 5 and count forward 2.

    The output is 7 because 5 + 2 = 7.
  2. 2

    Rule: Add 3. Complete the table: Input 1 gives Output 4. Input 2 gives Output 5. Input 3 gives Output blank. What is the missing output?

    The missing output is 6 because 3 + 3 = 6.
  3. 3

    Rule: Subtract 1. If the input is 9, what is the output?

    Start with 9 and count back 1.

    The output is 8 because 9 - 1 = 8.
  4. 4

    Rule: Add 5. Complete the table: Input 0 gives Output 5. Input 1 gives Output 6. Input 4 gives Output blank. What is the missing output?

    Add 5 to the input number.

    The missing output is 9 because 4 + 5 = 9.
  5. 5

    Rule: Double the input. If the input is 6, what is the output?

    Double means add the number to itself.

    The output is 12 because double 6 means 6 + 6 = 12.
  6. 6

    Look at the pairs: 2 goes to 4, 3 goes to 6, and 5 goes to 10. What is the rule?

    The rule is double the input because each output is two times the input.
  7. 7

    Rule: Add 10. Complete the table: Input 7 gives Output blank. Input 8 gives Output 18. Input 9 gives Output blank. What are the missing outputs?

    Add 10 to each input.

    The missing outputs are 17 and 19 because 7 + 10 = 17 and 9 + 10 = 19.
  8. 8

    Rule: Subtract 2. If the output is 6, what input was used?

    To find the input, do the opposite operation and add 2 to the output.

    The input was 8 because 8 - 2 = 6.
  9. 9

    Rule: Add 4. Complete the table: Input blank gives Output 10. What is the missing input?

    The missing input is 6 because 6 + 4 = 10.
  10. 10

    Look at the table: Input 1 gives Output 3. Input 2 gives Output 4. Input 5 gives Output 7. What is the rule?

    Compare each input to its output and see how much was added.

    The rule is add 2 because each output is 2 more than the input.
  11. 11

    Rule: Subtract 3. Complete the table: Input 8 gives Output 5. Input 10 gives Output blank. Input 12 gives Output blank. What are the missing outputs?

    Subtract 3 from each input.

    The missing outputs are 7 and 9 because 10 - 3 = 7 and 12 - 3 = 9.
  12. 12

    Rule: Add 1. The inputs are 4, 5, and 6. What are the outputs?

    The outputs are 5, 6, and 7 because each input has 1 added to it.
  13. 13

    A function machine uses the rule add 6. Nina puts in 3. What number comes out?

    The input is the number that goes into the machine.

    The number 9 comes out because 3 + 6 = 9.
  14. 14

    A function machine uses the rule double the input. Sam puts in 4, then 5, then 7. What numbers come out?

    The numbers 8, 10, and 14 come out because double 4 is 8, double 5 is 10, and double 7 is 14.
  15. 15

    Look at the pairs: 6 goes to 4, 8 goes to 6, and 9 goes to 7. What is the rule?

    Check how the output changes from the input in each pair.

    The rule is subtract 2 because each output is 2 less than the input.
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