Lesson 8.38.1–8.3 Catch-Up
Start hereWords, worked example, and sentence starters
Learning target I can show I am caught up on Lessons 8.1–8.3 by using each lesson's big idea in mixed practice.
Start hereWords for this lesson
Read each word before you begin. Say it out loud.
| Word | What it means | Example |
|---|---|---|
| Write EquationsSpanish: Escribir ecuaciones | Represent a relationship with expressions joined by an equal sign. | A $5 fee plus $3 per game for g games: 5 + 3g = total. |
| EquationSpanish: Ecuación | A math sentence with an equal sign showing both sides are the same. | n + 8 = 20 means 'some number plus 8 equals 20' |
| VariableSpanish: Variable | A letter that stands for a number that is unknown or can change. | In n + 3 = 10, the letter n stands for the unknown number (n = 7) |
| Equal signSpanish: Signo igual | The = sign, showing both sides are the same. | 7 + 3 = 10 — both sides equal 10 |
| ExpressionSpanish: Expresión | A math phrase with numbers and letters, but no equal sign. | 2x + 5 is an expression; it becomes an equation when you write 2x + 5 = 15 |
| ConstantSpanish: Constante | A fixed number in an expression or equation that does not change. | In x + 7 = 12, the numbers 7 and 12 are constants; only x can change. |
How it worksWorked examplesolving a multiplication equation
These numbers are not on your problems. The steps are. Follow them with your own numbers.
A stamp album has 7 pages that each hold p stamps. It holds 91 stamps in all. Solve 7p = 91.
- The variable p is multiplied by 7, so the inverse operation is division.
- Divide BOTH sides by 7 so the equation stays balanced.
- Left side: 7p ÷ 7 leaves p. Right side: 91 ÷ 7 gives 13.
- Check: 7 × 13 makes 91, so both sides are equal.
Answer: p = 13, so each page holds 13 stamps.
Now you trySame steps, your turn
The steps are the same as the worked example. The numbers are yours. Do the work.
A choir stands in 9 equal rows and has 108 singers. Solve 9r = 108 for the singers in one row.
- The variable r is multiplied by , so the inverse operation is .
- Divide both sides by .
- Left side leaves . Right side: 108 ÷ 9 = .
- Check: 9 × = . Does it balance?
Say it and write itSentence starters
Finish each sentence out loud with a partner. Then use them in your writing.
- The variable is multiplied by , so I both sides by it.
- My equation is because each group holds .
- The solution means in this problem.
- I checked my answer by multiplying and .
Word bank equationcoefficientmultiplydivideinverse operationisolateboth sidesequal groupssolutioncheckundobalance
Watch outA common mistake
A common mistake in Solve Multiplication and Division Equations is applying the SAME operation again instead of the inverse — for example, seeing 6x = 42 and multiplying both sides by 6 to get x = 252, instead of dividing by 6 to get x = 7. Before you submit, ask: did I use the OPPOSITE operation shown in the equation, and did I apply it to both sides?
Lesson 8.38.1–8.3 Catch-Up
Catch-UpSkill bridge
Learning target I can show I am caught up on Lessons 8.1–8.3 by using each lesson's big idea in mixed practice.
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1Circle the letter of the best answer. Show how you know.
(Lesson 8.1) Which equation represents: 'A number plus 12 equals 30'?
- An + 12 = 30
- Bn − 12 = 30
- C12n = 30
- Dn / 12 = 30
Hint Find the operation word in the sentence. What does 'plus' tell you to do with the number and 12?
Show your work -
2Circle the letter of the best answer. Show how you know.
(Lesson 8.1) Which equation represents: 'Seven less than a number is 18'?
- An − 7 = 18
- B7 − n = 18
- Cn + 7 = 18
- Dn / 7 = 18
Hint 'Seven less than a number' is tricky — the number comes FIRST, and then 7 is taken away from it.
Show your work -
3Circle the letter of the best answer. Show how you know.
(Lesson 8.2) Solve: x + 9 = 15
- Ax = 6
- Bx = 9
- Cx = 15
- Dx = 24
Hint x has 9 added to it. To get x alone, you need to UNDO that addition.
Show your work -
4Circle the letter of the best answer. Show how you know.
(Lesson 8.2) Solve: y − 7 = 20
- Ay = 7
- By = 13
- Cy = 27
- Dy = 140
Hint Look at what's happening to y: 7 is being SUBTRACTED. Which operation undoes subtraction?
Show your work -
5Circle the letter of the best answer. Show how you know.
(Lesson 8.3) Solve: 6x = 42
- Ax = 7
- Bx = 36
- Cx = 48
- Dx = 252
Hint 6x means 6 TIMES x — the variable is being multiplied by 6.
Show your work
Explain your thinkingHow do you decide whether to multiply or divide to solve an equation?
Sentence starter When I see ___ in the equation, I know to ___ both sides because the inverse of ___ is ___.