Grade 6 Mathematics · Unit 9: Relationships Between Two VariablesStandard 6.AT.11

Lesson 9.49.4 Small Group · Group 1

Start hereWords, worked example, and sentence starters

Name Date Period

Learning target With my small group, I can write an equation to represent the relationship between two variable quantities and use it to solve a real problem — one step at a time, with support.

Start hereWords for this lesson

Read each word before you begin. Say it out loud.

WordWhat it meansExample
solutionSpanish: solución A value of the variable that makes an equation true. the number you solve for
substituteSpanish: sustituir To replace a variable with a number so you can compute. put 8 in for x
at leastSpanish: al menos That amount or more — the smallest amount that still works. “At least $500” means $500 counts, and so does anything more.
predictSpanish: predecir To make a reasonable guess about a future amount using information you already have. We measured up to 5 minutes → 6,000 feet. Reach PAST what was measured: 6 minutes should be about 7,200.
justifySpanish: justificar To explain WHY an answer or recommendation makes sense, using the mathematics. “35 cars at $14.30 raises $500.50, which clears the $500 goal.”
EquationSpanish: Ecuación A math sentence with an equals sign showing two amounts are the same. c = 4n

How it worksWorked examplesubstituting to find the output

These numbers are not on your problems. The steps are. Follow them with your own numbers.

A press makes 22 posters each hour. Write an equation, then find the posters made in 15 hours.

  1. Define: h = hours running, p = posters made. Posters depend on hours.
  2. The rate is 22 posters for each hour, so the rule is p = 22h.
  3. Substitute 15 for h: 22 × 15 → 330 posters.
  4. Check the context: many more hours gave a much larger count, so this fits.

Answer: p = 22h, so a 15-hour run makes 330 posters.

Now you trySame steps, your turn

The steps are the same as the worked example. The numbers are yours. Do the work.

A juicer fills 13 bottles each minute. Write an equation, then find the bottles filled in 40 minutes.

  1. Define: m = , b = .
  2. The rate is bottles for each minute, so the rule is b = m.
  3. Substitute 40 for m: × 40 → bottles.
  4. Check the context: does your answer fit that many minutes?
Answer:equation; bottles in 40 minutes

Say it and write itSentence starters

Finish each sentence out loud with a partner. Then use them in your writing.

  • I let stand for and stand for .
  • My equation is , so I substitute for .
  • The solution is , which means in this situation.
  • This answer is reasonable because .

Word bank equationsubstitutesolutionratevariablemultiplypertotalreasonablecheckinputoutput

Watch outA common mistake

Adding the rate instead of multiplying — writing 2.5 + 8 = 10.5 cars for an 8-hour shift instead of 2.5 × 8 = 20. The rate applies to EVERY hour, so the total is always rate × amount.

Grade 6 Mathematics · Unit 9: Relationships Between Two VariablesStandard 6.AT.11

Lesson 9.49.4 Small Group · Group 1

Group 1Supported practice

Mastery check☐ Exceeds☐ Meets target☐ Needs practice
Name Date Period

Learning target With my small group, I can write an equation to represent the relationship between two variable quantities and use it to solve a real problem — one step at a time, with support.

  1. 1Complete each step, then write the final answer.
    05101520253035404550051015202530354045505560Hours (h)Cakes made (c)(0, 0)(10, 15)
    The bakery makes 1.5 cakes each hour.

    A bakery makes 1.5 cakes every hour. It gets an order for 60 cakes. Let h = hours and c = cakes. How many hours does the bakery need? It works 8 hours a day. How many days is that?

    1. 1Write an equation for the cakes made in h hours.
    2. 2Substitute 60 for c. What equation do you get?
    3. 3Divide both sides by 1.5. How many hours?
    4. 4The bakery works 8 hours a day. How many days is that?
    Final answer:
  2. 2Complete each step, then write the final answer.
    Bracelets1?Money raised$3$100× ?× ?
    Each bracelet raises $3.

    A club sells bracelets for $3 each. Their goal is $100. Let b = bracelets sold and t = total raised. How many bracelets must they sell?

    1. 1Write 1 bracelet → $3. What scale factor takes $3 to $100?
    2. 2How much money do 33 bracelets raise?
    3. 3What is the least number of bracelets that reaches $100?
    Final answer:
  3. 3Complete each step, then write the final answer.
    Minutes1?Boxes545× ?× ?
    The machine fills 5 boxes each minute.

    A machine fills 5 boxes every minute. Let m = minutes and b = boxes. How many minutes does it take to fill 45 boxes?

    Show your work

    Hint The equation is b = 5m. Put in 45 for b. Then divide both sides by 5.

    Final answer:
  4. 4Complete each step, then write the final answer.
    Hours1?Bikes3.5280× ?× ?
    The factory makes 3.5 bikes each hour.

    A factory makes 3.5 bikes every hour. Let h = hours and b = bikes. How many hours does the factory need to make 280 bikes?

    Show your work

    Hint Write b = 3.5h. Put in 280 for b. Which operation undoes multiplying by 3.5?

    Final answer:
  5. 5Complete each step, then write the final answer.
    Plants1?Money earned$8$150× ?× ?
    Each plant earns $8.

    A school earns $8 for each plant it sells. The goal is $150. Let p = plants sold. What is the least number of plants they must sell to reach the goal?

    Show your work

    Hint Solve 8p = 150. The answer is not whole. Check the whole numbers on each side of it.

    Final answer:
  6. 6Circle the letter of the best answer. Show how you know.
    Notebooks167Cost$3??× ?× ?× ?× ?
    Each notebook costs $3. Kim has $20.

    Kim has $20. Notebooks cost $3 each. She solves 3n = 20 and gets n ≈ 6.7. She says she can buy 7 notebooks. Is she right?

    1. ANo. 7 notebooks cost $21, so she can buy 6.
    2. BYes. 6.7 rounds up to 7.
    3. CNo. She can buy 6.7 notebooks.

    Hint Find the cost of 7 notebooks. Can Kim pay for them with $20?

    Show your work

Explain your thinkingThe bracelets needed 34, not 33.3. Kim could buy 6, not 6.7. When do you round up, and when do you round down?

Sentence starter I round up when ___. · I round down when ___.

How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help