Choosing a tool or representation · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Picking the right tool

Mathematics · Mathematical Thinking · ages 6-7
Name ______________________   Date ____________

  1. You need to add 23 and 10. Which tool can help you count on?

    • Ruler
    • Number line
    • None, you can't use a tool

  2. Which tool would help you measure the length of a table?

    • Number line
    • Ruler
    • Hundred square

  3. A ruler is the best tool for adding two numbers together.

    Circle one:   True   False

  4. Use the number line. Start at 34 and hop forward 20. Where do you land?

    30343942454851545760+20

    Answer: ______________

  5. Ben takes 30 away from 65 by making three backward hops of ten. Which tool is he using?

    • Hundred square
    • Number line
    • Ruler

  6. Why might you use a hundred square instead of counting in your head for 46 + 30?

    • It's more fun to draw
    • You can see each ten as you count on, so you don't lose track
    • It's the only way to add numbers

  7. Priya is solving 58 + 24. Which tool would help her see the tens and ones as she counts on?

    • A ruler
    • A hundred square
    • A single dot on paper

  8. Tom is measuring a pencil but picks a number line instead of a ruler. What went wrong?

    • Nothing, a number line measures length just as well
    • He picked a tool for counting, not for measuring length
    • He should have used a hundred square instead
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Picking the right tool W1-mt_zMEvtigoM3-s1

  1. Number line · A number line lets you hop from 23 up by 10 to find the answer.
  2. Ruler · A ruler is made for measuring length, not for counting or adding.
  3. False · A ruler measures length. For adding, a number line or hundred square works better.
  4. 54 · Hopping from 34 by 20 lands you on 54.
  5. Number line · Hops between numbers are what a number line shows. A hundred square would show the same jump as three rows, and a ruler measures length.
  6. You can see each ten as you count on, so you don't lose track · A hundred square shows tens in rows, so you can count on without losing your place.
  7. A hundred square · A hundred square lays out numbers in rows of ten, which helps when adding two-digit numbers.
  8. He picked a tool for counting, not for measuring length · A number line helps you count or add. Measuring length needs a ruler.
Worksheet · LightMySky