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Unit 07 · Equations Inequalities and RelationshipsLesson

Day 097One Step Equation Models

LearnClassworkAnswer keyPDF packet ↗
Standards 6.EE.B.66.EE.B.7
LEARNING TARGET

I can model a situation with a one-step equation and solve it.

01 · LEARN

Build the idea

Define the unknown quantity. Translate the relationship into an equation before calculating. Use the inverse operation and check whether the answer makes sense in the situation.

WORKED EXAMPLE 1

A collection grows by 3 cards to 6 cards. Let x be the starting count. Write and solve an equation.

x + 3 = 6; x = 3 cards

Subtract 3 from both sides; 3 + 3 = 6.

WORKED EXAMPLE 2

5 identical lengths of rope total 35/2 m. Let x be the length of one piece. Write and solve an equation, then check.

5x = 35/2; x = 7/2 m

Divide the total by 5: 35/2 ÷ 5 = 7/2.

02 · PRACTICE

Your turn

Work in order. Start with the foundations, then build toward explanation and application.

  1. A collection grows by 4 cards to 12 cards. Let x be the starting count. Write and solve an equation.

  2. A collection grows by 8 cards to 56 cards. Let x be the starting count. Write and solve an equation.

  3. A collection grows by 3 cards to 6 cards. Let x be the starting count. Write and solve an equation.

  4. 7 identical lengths of rope total 28 m. Let x be the length of one piece. Write and solve an equation, then check.

  5. 5 identical lengths of rope total 10 m. Let x be the length of one piece. Write and solve an equation, then check.

  6. 6 identical lengths of rope total 24 m. Let x be the length of one piece. Write and solve an equation, then check.

  7. 4 identical lengths of rope total 16 m. Let x be the length of one piece. Write and solve an equation, then check.

  8. 2 identical lengths of rope total 6 m. Let x be the length of one piece. Write and solve an equation, then check.

  9. 3 identical lengths of rope total 9/2 m. Let x be the length of one piece. Write and solve an equation, then check.

  10. 5 identical lengths of rope total 20 m. Let x be the length of one piece. Write and solve an equation, then check.

03 · CHECK

Answers and reasoning

Reveal the teacher answer key
  1. x + 4 = 12; x = 8 cards

    Subtract 4 from both sides; 8 + 4 = 12.

  2. x + 8 = 56; x = 48 cards

    Subtract 8 from both sides; 48 + 8 = 56.

  3. x + 3 = 6; x = 3 cards

    Subtract 3 from both sides; 3 + 3 = 6.

  4. 7x = 28; x = 4 m

    Divide the total by 7: 28 ÷ 7 = 4.

  5. 5x = 10; x = 2 m

    Divide the total by 5: 10 ÷ 5 = 2.

  6. 6x = 24; x = 4 m

    Divide the total by 6: 24 ÷ 6 = 4.

  7. 4x = 16; x = 4 m

    Divide the total by 4: 16 ÷ 4 = 4.

  8. 2x = 6; x = 3 m

    Divide the total by 2: 6 ÷ 2 = 3.

  9. 3x = 9/2; x = 3/2 m

    Divide the total by 3: 9/2 ÷ 3 = 3/2.

  10. 5x = 20; x = 4 m

    Divide the total by 5: 20 ÷ 5 = 4.

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