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You did these with your group. Now do them on your own — the model above is yours to copy.

1. 1

   Same stepsFinish what the group started. Use the model above, step for step.

   Let's try together: New clue: 'A number plus 5 equals 9.' What is the unknown? We let n be the unknown. What does 'plus 5' tell us to write? What does 'equals 9' tell us? Put it together: n + 5 = 9.

   My first step is ___ , because the problem asks for ___ .

   Show your work
2. 2

   Warm restartReflect the point (4, 3) across the x-axis. What are the new coordinates?

   1. A(4, −3)
   2. B(−4, 3)
   3. C(−4, −3)
   4. D(3, 4)
3. 3

   Warm restartReflect the point (−2, 5) across the y-axis.

   1. A(2, 5)
   2. B(−2, −5)
   3. C(2, −5)
   4. D(5, −2)
4. 4

   Warm restartWhen you reflect a point across the x-axis, which coordinate changes sign?

   1. AThe y-coordinate
   2. BThe x-coordinate
   3. CBoth of them
   4. DNeither of them

You answered these out loud. Now write them.

Answer, then say how you know — the reason is the part that counts.

1. 5

   Think it throughSolve p + 14 = 37.

   1. Ap = 23
   2. Bp = 51
   3. Cp = 14
   4. Dp = 37

   Why is that the answer?

   I chose ___ because ___ .
2. 6

   Think it throughWhy subtract 14 from BOTH sides?

   1. ATo keep the equation balanced while isolating p
   2. BBecause subtraction is easier than addition
   3. CBecause 14 is the smaller number
   4. DTo make the answer a whole number

   How do you know?

   I chose ___ because ___ .
3. 7

   Think it throughCheck your answer: does 23 work?

   1. AYes — 23 + 14 = 37
   2. BNo — 23 + 14 = 47
   3. CNo — 23 − 14 = 9
   4. DYou cannot check an equation

   Explain your thinking.

   I chose ___ because ___ .
4. 8

   Back to the modelHow did you decide what expression to put on each side of the balance?

   I put ___ on the left side because ___, and ___ on the right side because ___. The equal sign means ___.

Use the words

Fill each blank with a word from the bank.

• Two expressions joined by an ___ ___ make an equation.
• A math sentence that says two amounts are equal, with an = sign, is an ___.
• A letter that stands for an unknown number is a ___.
• The symbol = that shows two amounts are the same is the ___.

Explain the thinking

1. 9

   Find the mistakeAnother student made this exact mistake in this lesson. Explain why it is wrong, then write what they should have done.

   The mistake: A common mistake in Write Equations is writing subtraction and division clues in the wrong order — putting the number from the clue first instead of the variable first.
2. 10

   Say moreOn the balance scale you put n + 8 on one side and 20 on the other. How did you decide what belongs on each side of the equal sign?

   I put ___ on the left side because ___.
3. 11

   Change one numberGo back to Part 1 and pick one problem you already solved. Change one number in it, then solve your new version. Show every step.

   If ___ changed to ___ , then ___ .

   Show your work

Last check

These two come from Lesson 7.9. If they are shaky, that is the lesson to revisit — not this one.

1. 12

   Show what you knowQuick check — you've got this: Which value is the solution of n + 5 = 9, and how do you know?

   1. An = 4, because 4 + 5 = 9 is true
   2. Bn = 14, because 9 + 5 = 14
   3. Cn = 3, because 3 is close to 4
   4. Dn = 5, because 5 appears in the equation

   Explain your choice.

   I know it is ___ because ___ .
2. 13

   From Lesson 7.9Quick check — you've got this: What is the reflection of (-5, 2) over the y-axis?

   1. A(-5, -2)
   2. B(5, -2)
   3. C(5, 2)
   4. D(2, -5)
3. 14

   From Lesson 7.9Reflecting over the y-axis changes which coordinate?

   1. AOnly the x-coordinate
   2. BOnly the y-coordinate
   3. CBoth coordinates
   4. DNeither coordinate

Be honest — this tells your teacher what to do next