Using structure in numbers and shapes · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Spotting structure: numbers and shapes

Mathematics · Mathematical Thinking · ages 7-8
Name ______________________   Date ____________

  1. What is 572 + 300?

    Answer: ______________

  2. What happens to 345 when you add 200?

    • Only the hundreds digit changes
    • Only the ones digit changes
    • Every digit changes
    • Nothing changes

  3. 200 + 45 = 245. If you do 300 + 45 instead, what changes?

    • Only the hundreds digit
    • The tens digit too
    • The ones digit too

  4. Which shape has exactly 3 sides?

    • Triangle
    • Rectangle
    • Pentagon

  5. A pack has 54 stickers shared equally among 6 friends. How many stickers does each friend get?

    Answer: ______________

  6. A shape has 4 sides, but no right angles and no parallel sides. Could it be a rectangle?

    • No, a rectangle needs 4 right angles and parallel sides
    • Yes, any 4-sided shape is a rectangle
    • Yes, as long as it has 4 corners

  7. You know 7 x 8 = 56. Which fact in the same fact family does that give you?

    • 56 + 7 = 63
    • 7 + 8 = 15
    • 56 / 7 = 8
    • 56 - 7 = 49

  8. Omar says adding hundreds only changes the hundreds digit. Is Omar right?

    Circle one:   True   False

  9. Ravi says 250 + 600 = 850, then finds 250 + 700 by changing only the tens digit. Is his method right?

    • No, 600 to 700 is a change in the hundreds digit, not the tens digit
    • Yes, that's correct
    • No, you must recalculate everything from scratch

  10. A box holds 3 rows of 8 cakes. How many cakes is that?

    Answer: ______________

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Answer key

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

Spotting structure: numbers and shapes W1-mt_FAXjFkgG6X-s1

  1. 872 · 5 hundreds plus 3 hundreds is 8 hundreds, so 872.
  2. Only the hundreds digit changes · 200 is 2 hundreds and no tens or ones, so only the hundreds digit grows.
  3. Only the hundreds digit · Adding to the hundreds place only changes the hundreds digit. 45 stays 45.
  4. Triangle · A triangle is defined by having 3 sides and 3 corners.
  5. 9 · 54 / 6 = 9, which fits because 6 x 9 = 54.
  6. No, a rectangle needs 4 right angles and parallel sides · A rectangle must have 4 right angles and 2 pairs of parallel sides, not just 4 sides.
  7. 56 / 7 = 8 · Division undoes multiplication, so 56 split into 7 groups gives 8.
  8. True · Omar is right. Whole hundreds carry no tens or ones, so the other digits stay put.
  9. No, 600 to 700 is a change in the hundreds digit, not the tens digit · 600 to 700 changes the hundreds place, so the hundreds digit of the answer changes too: 250 + 700 = 950.
  10. 24 · 3 rows of 8 is 3 x 8 = 24, the same as 8 x 3 by commutativity.
Worksheet · LightMySky