Grade 6 Mathematics · Unit 2: Understanding the World Around Us Through StatisticsStandard 6.DS.4

Lesson 2.8Reaching a Target Mean

Start hereWords, worked example, and sentence starters

Name Date Period

Learning target I can determine the mean of a data set, use a target mean to find a missing value, and explain the mean as the fair share and the balance point of the data.

Start hereWords for this lesson

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

WordWhat it meansExample
MeanSpanish: Media The average of a data set. Add all the values, then divide by how many values there are. Add, then divide by the count
AverageSpanish: Promedio Another word for the mean — the amount each value would be if the total were shared equally. A player averages 15 points per game, so over 10 games she scores 15 × 10 = 150 points in all.
Measure of centerSpanish: Medida de centro A single number used to describe the middle, or typical value, of a whole data set. The mean, $15, is one measure of center that describes all four of Miguel's days at once.
Balance pointSpanish: Punto de equilibrio The value where the total distance of the data above it equals the total distance below it. The mean is the balance point. The mean balances the set
Data setSpanish: Conjunto de datos The whole collection of values that were gathered or measured. Sofia's points in games 1–9 — 12, 20, 16, 11, 17, 14, 15, 10, 18 — form one data set.
Target meanSpanish: Media objetivo The mean a person is trying to reach. A goal average of 29

How it worksWorked example

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

Quiz scores are 6, 7 and 9. What fourth score gives a mean of 8?

  1. Count all scores, with the missing one: 4.
  2. Target total: 8 × 4 = 32. Sum so far: 6 + 7 + 9 = 22.
  3. 32 − 22 = 10. Check: 6 + 7 + 9 + 10 = 32 and 32 ÷ 4 = 8.

Answer: The fourth score is 10.

Say it and write itSentence starters

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

  • A target mean of over values needs a total of .
  • The values so far add to .
  • The missing value must be because .
  • I checked by .

Word bank target meantarget totalmissing valuesumcountmultiplysubtractaveragebalancecheckgoaldata set

Watch out!A common mistake

The most common mistake with the mean is adding correctly and then dividing by the wrong number

Grade 6 Mathematics · Unit 2: Understanding the World Around Us Through StatisticsStandard 6.DS.4

Lesson 2.8Reaching a Target Mean

Apply Day · Version ASupported practice

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

Learning target I can determine the mean of a data set, use a target mean to find a missing value, and explain the mean as the fair share and the balance point of the data.

  1. 1Complete each step, then write the final answer.

    Find the mean of 2, 4, 6, 8.

    Show your work

    Hint Add the four values. Then divide the total by 4.

    Final answer:
  2. 2Complete each step, then write the final answer.

    Find the mean of 10, 20, 15, 25, 30.

    Show your work

    Hint Add the five values. Then divide the total by 5.

    Final answer:
  3. 3Complete each step, then write the final answer.

    Ali read 6, 3, 8 and 7 books in 4 months. What is the mean number of books per month?

    Show your work

    Hint Add the books for all 4 months. Then divide the total by 4.

    Final answer:
3-Point Exit Checklist: ☐ 1. Units & Labels Verified ☐ 2. Mathematical Reasoning Stated ☐ 3. Calculations Double-Checked
How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help
Grade 6 Mathematics · Unit 2: Understanding the World Around Us Through StatisticsStandard 6.DS.4

Lesson 2.8Reaching a Target Mean

Apply Day · Version BCore practice

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

Learning target I can determine the mean of a data set, use a target mean to find a missing value, and explain the mean as the fair share and the balance point of the data.

  1. 1Complete each step, then write the final answer.

    Omar finds the mean of 6, 9, 3 and 10. He adds them and gets 28. He says the mean is 28. What is the mean?

    Show your work
    Final answer:
  2. 2Complete each step, then write the final answer.

    Find the mean of 2.5, 4, 6.5 and 3.

    Show your work
    Final answer:
  3. 3Complete each step, then write the final answer.

    Find the mean of 10, 14, 12, 16.

    Show your work
    Final answer:
3-Point Exit Checklist: ☐ 1. Units & Labels Verified ☐ 2. Mathematical Reasoning Stated ☐ 3. Calculations Double-Checked
How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help
Grade 6 Mathematics · Unit 2: Understanding the World Around Us Through StatisticsStandard 6.DS.4

Lesson 2.8Reaching a Target Mean

Apply Day · ChallengeExtension

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

Learning target I can determine the mean of a data set, use a target mean to find a missing value, and explain the mean as the fair share and the balance point of the data.

  1. 1Circle the letter of the best answer. Show how you know.

    Find the mean of this data set: 6, 10, 14, 8, 12.

    1. A8
    2. B10
    3. C12
    4. D50
    Put the data in order
    Work
  2. 2Complete each step, then write the final answer.

    The mean of 6, 10 and 14 is 10. A new value, 2, is added. Nina says the mean stays 10. What is the new mean?

    Show your work
    Final answer:
  3. 3Complete each step, then write the final answer.

    The mean of 5 quiz scores is 7. Four scores are 6, 9, 4 and 8. What is the fifth score?

    Show your work
    Final answer:
3-Point Exit Checklist: ☐ 1. Units & Labels Verified ☐ 2. Mathematical Reasoning Stated ☐ 3. Calculations Double-Checked
How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help