Grade 6 Mathematics · Unit 6: Numerical and Algebraic ExpressionsStandard 6.AT.6c

Lesson 6.46.4 Small Group · Group 1

Start hereWords, worked example, and sentence starters

Name Date Period

Learning target With my small group, I can write numerical expressions from a real situation and evaluate them using the order of operations, including powers — 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
Numerical expressionSpanish: Expresión numérica A math phrase built from numbers and operations, with no equal sign and no variable. 4 × 9 + 3 × 6
EvaluateSpanish: Evaluar To find the single value an expression is worth by carrying out its operations in order. 3 × 6 = 18
Order of operationsSpanish: Orden de las operaciones The agreed order for evaluating: grouping symbols, then exponents, then multiply and divide left to right, then add and subtract left to right. 3 + 4 × 2² → 3 + 4 × 4 → 3 + 16 = 19
PowerSpanish: Potencia A short way to write repeated multiplication of the same factor, such as 2³ for 2 × 2 × 2. 8 × 8 = 8^2
BaseSpanish: Base In a power, the number being multiplied by itself. In 2³ the base is 2. In 8^2, the base is 8.
ExponentSpanish: Exponente In a power, the small raised number that says how many times the base is used as a factor. In 8^2, the exponent is 2.

How it worksWorked examplewriting an expression from a situation

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

A group buys 4 tickets at $9 each and 3 programs at $6 each. Write an expression for the total cost, then find it.

  1. Name the parts. tickets: 4 at $9 programs: 3 at $6
  2. Write a product for each part. 4 × 9 and 3 × 6
  3. Join them with the operation the story needs. 4 × 9 + 3 × 6
  4. Evaluate. 36 + 18 = 54

Answer: The expression is 4 × 9 + 3 × 6, and the total cost is $54.

Now you trySame steps, your turn

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

A team buys 7 shirts at $11 each and 2 hats at $8 each. Write an expression for the total cost, then find it.

  1. Name the parts. shirts: at $ hats: at $
  2. Write a product for each part. × and ×
  3. Join them with the right operation.
  4. Evaluate. + =
Answer:expression and total cost in dollars

Say it and write itSentence starters

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

  • The word tells me to multiply by .
  • The expression for this situation is .
  • I used a power because the same factor repeats times.
  • An expression has no equal sign, so I only it.

Word bank numerical expressionevaluatepowerbaseexponentproductsumdifferenceeachin alloperationvalue

Watch outA common mistake

A common mistake with powers is multiplying the base by the exponent: reading 3² as 3 × 2 = 6 instead of 3 × 3 = 9. A second is evaluating strictly left to right, so 3 + 4 × 2 becomes 14 instead of 11. The order of operations exists so one expression has exactly one value: grouping symbols, then powers, then × and ÷ left to right, then + and − left to right.

Grade 6 Mathematics · Unit 6: Numerical and Algebraic ExpressionsStandard 6.AT.6c

Lesson 6.46.4 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 numerical expressions from a real situation and evaluate them using the order of operations, including powers — one step at a time, with support.

  1. 1Complete each step, then write the final answer.
    TicketNumberPriceCost
    Adult3$123 × 12
    Child53² dollars5 × 3²
    Each row is one part of the expression.

    Ana buys 3 adult tickets at $12 each and 5 child tickets at 3² dollars each. Write and evaluate an expression for the total cost.

    1. 1Write one expression for the total cost.
    2. 2Find the power first. What is 3²?
    3. 3Multiply, then add. What is the total cost?
    Final answer:
  2. 2Complete each step, then write the final answer.
    OrderWork
    1. Power2⁴ = ?
    2. Multiply3 × ?
    3. Subtract? − 12
    Powers, then multiply, then subtract.

    Mr. Lee buys 3 boxes of pencils. Each box has 2⁴ pencils. He gives away 12 pencils. Write and evaluate an expression for the pencils he has left.

    1. 1Write one expression for the pencils left.
    2. 2Find the power first. What is 2⁴?
    3. 3Multiply, then subtract. How many pencils are left?
    Final answer:
  3. 3Complete each step, then write the final answer.

    Evaluate 4 + 2 × 3².

    Show your work

    Hint Find the power first. Then multiply. Add last.

    Final answer:
  4. 4Complete each step, then write the final answer.

    Evaluate 5 × 15 + 2 × 20 + 3 × 2³.

    Show your work

    Hint Find 2³ first. Then do each multiplication. Add last.

    Final answer:
  5. 5Complete each step, then write the final answer.
    ItemNumberPriceCost
    Water6$26 × 2
    Pretzel42² dollars4 × 2²
    Add the two costs in one expression.

    A snack stand sells 6 waters at $2 each and 4 pretzels at 2² dollars each. Write and evaluate an expression for the total cost in dollars.

    Show your work

    Hint The expression is 6 × 2 + 4 × 2². Find the power before you multiply.

    Final answer:
  6. 6Complete each step, then write the final answer.

    Kim evaluates 3 + 4 × 5². She adds 3 + 4 first and gets 175. Is she right? Find the correct value.

    Show your work

    Hint Add comes last. What must you do before you add?

    Final answer:

Explain your thinkingKim added first and got 175. Why must you find the power and multiply before you add?

Sentence starter First I find ___ because ___. · Kim's answer is wrong because ___.

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