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3rd grade · Math · Unit 8 of 18

Patterns & Equations

Pattern rules and mystery numbers

What your child practices

Extending increasing and decreasing patterns, describing pattern rules in words and tables, and solving one-step equations like ☐ + 8 = 23.

Texas Essential Knowledge and Skills (TEKS) teks student expectation: 3.5(D); 3.5(E) · finding unknown numbers in equations and describing number pairs in tables

How we explain it

Children can open this short lesson before they practice.

  1. An equation has an = sign. Both sides are the same.
  2. A letter or box stands for a missing number.
  3. Do the opposite to find it: the opposite of + is −.

Example: n + 7 = 15 Undo + 7 by taking away 7. 15 − 7 = 8. Answer: n = 8

Patterns & Equations in Texas

In the Texas Essential Knowledge and Skills (TEKS), this is unit 8 of 18 in 3rd grade Math, after Division and before Fractions.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Texas Education Agency (TEA)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Which equation matches the story? The is the number we don't know.

    Jay had 45 stickers.

    Jay gave some to friends.

    Now Jay has 25.

    • 45 + 25 = ☐
    • ☐ − 45 = 25
    • 45 − ☐ = 25

  2. Question 2

    Which pattern rule fits?

    499, 599, 699, 799

    • Start at 499 and add 100 each time
    • Start at 599 and add 100 each time
    • Start at 499 and subtract 100 each time
    • Start at 499 and add 200 each time

  3. Question 3

    What number is missing from the pattern?

    37, 34, 31, , 25

    answer box

  4. Question 4

    What number goes in the box?

    18 + = 25

    • 8
    • 43
    • 6
    • 7

  5. Question 5

    What number comes next?

    50, 100, 150, 200,

    • 250
    • 251
    • 249
    • 300

  6. Question 6

    What number goes in the box?

    + 34 = 98

    answer box

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