# McGraw Hill My Math Grade 4 Chapter 7 Lesson 7 Answer Key Order of Operations

All the solutions provided inÂ McGraw Hill My Math Grade 4 Answer Key PDF Chapter 7 Lesson 7 Order of Operations will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 4 Answer Key Chapter 7 Lesson 7 Order of Operations

An expression is a combination of numbers, variables, and at least one operation.
When an expression has more than one operation, the order of operations tells us which one to perform first, so that everyone gets the same answer. Parentheses () are symbols which indicate how to group operations.

Math in My World
Example 1
The table shows how much movie tickets cost. How much will it cost to buy 3 adult tickets and 5 child tickets?

cost = 3 adult tickets + 5 child tickets

So, the total cost is $____________. Answer: Total cost to buy 3 adult tickets and 5 child tickets =$49.

Explanation:
Cost of movie ticket for an adult = $8. Number of adults = 3. Cost of movie ticket for a child =$5.
Number of children = 5.
Total cost of movie ticket for an adults = Number of adults Ă— Cost of movie ticket for an adult
= 3 Ă— $8 =$24.
Total cost of movie ticket for children = Number of children Ă— Cost of movie ticket for a child
= 5 Ă— $5 =$25.
Total cost to buy 3 adult tickets and 5 child tickets = Total cost of movie ticket for an adults + Total cost of movie ticket for children
= $24 +$25
= $49. Remember, an expression is a combination of numbers, variables, and at least one operation. Example 2 Find the value of the expression 3 Ă— (4 + 6). So, 3 Ă— (4 + 6) = _____________. Answer: So, 3 Ă— (4 + 6) = 30. Explanation: Expression 3 Ă— (4 + 6): 3 Ă— (4 + 6) = 3 Ă— 10 = 30. Example 3: Find the value of the expression (7 – 3) Ă· (2 + 2). So, (7 – 3) Ă· (2 + 2) = _____________. Answer: So, (7 – 3) Ă· (2 + 2) = 1. Explanation: Expression (7 – 3) Ă· (2 + 2): (7 – 3) Ă· (2 + 2) = 4 Ă· 4 = 1. Talk Math Explain why Examples 2 and 3 have different answers even though the numbers are the same. Answer: Examples 2 and 3 have different answers even though the numbers are the same because they both have different process to solve Example 2 Multiplication and Example 3 Division. Explanation: Example 2: 3 Ă— (4 + 6) = 30. Example 3: (7 – 3) Ă· (2 + 2) = 1. Example 2 Multiplication and Example 3 Division. Guided Practice Find the value of each expression. Question 1. 12 – 1 Ă— 3 = _______________ Answer: The value of 12 – 1 Ă— 3 expression = 9. Explanation: 12 – 1 Ă— 3 = 12 – 3 = 9. Question 2. 15 – 4 Ă— 2 = _______________ Answer: The value of 15 – 4 Ă— 2 expression = 7. Explanation: 15 – 4 Ă— 2 = 15 – 8 = 7. Question 3. (15 – 4) Ă— 2 = ________________ Answer: The value of (15 – 4) Ă— 2 expression = 22. Explanation: (15 – 4) Ă— 2 = 11 Ă— 2 = 22. Independent Practice Find the value of each expression. Question 4. 8 + 5 Ă— 2 = ________________ Answer: The value of 8 + 5 Ă— 2 expression = 18. Explanation: 8 + 5 Ă— 2 => 8 + 10 => 18. Question 5. 10 – 1 Ă— 5 = _______________ Answer: The value of 10 – 1 Ă— 5 expression = 5. Explanation: 10 – 1 Ă— 5 => 10 – 5 => 5. Question 6. 4 + 6 Ă· 2 = _____________ Answer: The value of 4 + 6 Ă· 2 expression = 7. Explanation: 4 + 6 Ă· 2 => 4 + 3 => 7. Question 7. 9 Ă— 2 – 6 = _____________ Answer: The value of 9 Ă— 2 – 6 expression = 12. Explanation: 9 Ă— 2 – 6 => 18 – 6 => 12. Question 8. (16 + 2) Ă· 3 = ____________ Answer: The value of (16 + 2) Ă· 3 expression = 9. Explanation: (16 + 2) Ă· 3 => 18 Ă· 3 => 9. Question 9. 6 Ă— (6 – 2) = ____________ Answer: The value of 6 Ă— (6 – 2) expression = 24. Explanation: 6 Ă— (6 – 2) => 6 Ă— 4 => 24. Question 10. (12 – 4) Ă· 4 = _______________ Answer: The value of (12 – 4) Ă· 4 expression = 2. Explanation: (12 – 4) Ă· 4 => 8 Ă· 4 => 2. Question 11. 12 – (4 Ă· 4) = ______________ Answer: The value of 12 – (4 Ă· 4) expression = 11. Explanation: 12 – (4 Ă· 4) => 12 – 1 => 11. Question 12. (3 + 6) Ă· (3 Ă— 1) = ______________ Answer: The value of (3 + 6) Ă· (3 Ă— 1) expression = 3. Explanation: (3 + 6) Ă· (3 Ă— 1) => 9 Ă· 3 => 3. Question 13. 3 + (6 Ă· 3) Ă— 1 = _______________ Answer: The value of 3 + (6 Ă· 3) Ă— 1 expression = 5. Explanation: 3 + (6 Ă· 3) Ă— 1 => 3 + 2 Ă— 1 => 3 + 2 => 5. Algebra Use the order of operations to find the unknown in each equation. Question 14. 5 Ă— 4 – = 13 The unknown is ______________. Answer: 5 Ă— 4 – = 13. The unknown is 7. Explanation: 5 Ă— 4 – ?? = 13 => 20 – ?? = 13 => 20 – 13 = ?? => 7 = ??. Question 15. Ă— (8 + 6) = 42 The unknown is ______________. Answer: Ă— (8 + 6) = 42. The unknown is 3. Explanation: ?? Ă— (8 + 6) = 42 => ?? Ă— 14 = 42 => ?? = 42 Ă· 14 => ?? = 3. Question 16. (2 + 1) Ă— (9 – ) = 12 The unknown is ______________. Answer: (2 + 1) Ă— (9 – ) = 12 The unknown is 5. Explanation: (2 + 1) Ă— (9 – ??) = 12 => 3 Ă— (9 – ??) = 12 =>Â (9 – ??) = 12 Ă· 3 =>Â (9 – ??) = 4. => 9 – 4 = ?? => 5 = ?? Question 17. (10 Ă· 2) + ( + 3) = 40 The unknown is ______________. Answer: (10 Ă· 2) + ( + 3) = 40. The unknown is ______________. Explanation: (10 Ă· 2) + (??Â + 3) = 40. => 5 + (??Â + 3) = 40. Problem Solving Question 18. Each bag of dried apples has 5 servings. Each bag of dried apricots has 3 servings. How many servings of dried fruit are in 6 bags of dried apples and 2 bags of dried apricots? Answer: Number of servings of dried fruit are in 6 bags of dried apples and 2 bags of dried apricots = 36. Explanation: Number of serving each bag of dried apples has = 5. Number of serving each bag of dried apricots has = 3. Number of bags of dried apples = 6. Number of bags of dried apricots = 2. Number of servings of dried fruit are in 6 bags of dried apples and 2 bags of dried apricots = (Number of serving each bag of dried apples has Ă— Number of bags of dried apples) + (Number of serving each bag of dried apricots has Ă— Number of bags of dried apricots) = (5 Ă— 6) + (3 Ă— 2) = 30 + 6 = 36. Question 19. Each book costs$4. How much does it cost to buy 3 books and one magazine that costs $5? Answer: Total cost to buy 3 books and one magazine that costs$5 = $17. Explanation: Cost of each book =$4.
Number of books = 3.
Cost of each magazine = $5. Number of magazine =Â 1. Total cost to buy 3 books and one magazine that costs$5 = (Cost of each book Ă— Number of books) + (Cost of each magazine Ă— Number of magazine)
= ($4 Ă— 3) + ($5 Ă— 1)
= $12 +$5
= $17. Question 20. Mathematical PRACTICE Use Number Sense A sandwich costs$6 and a drink costs $3. How much does it cost to buy 4 sandwiches and 4 drinks? Answer: Total cost to buy 4 sandwiches and 4 drinks =$36.

Explanation:
Cost of a sandwich = $6. Number of sandwiches = 4. Cost of a drink =$3.
Number of drinks = 4.
Total cost to buy 4 sandwiches and 4 drinks = (Cost of a sandwich Ă— Number of sandwiches) + (Cost of a drink Ă— Number of drinks)
= ($6 Ă— 4) + ($3 Ă— 4)
= $24 +$12
= $36. HOT Problems Question 21. Mathematical PRACTICE Keep Trying Use each of the numbers 1, 2, 3, and 4 exactly once in the equation below to make the equation true. ( Ă— ) + ( Ă· ) = 10 Answer: Equation that is true: Explanation: Numbers 1, 2, 3, and 4 exactly once in the equation: Equation: (1 Ă— 3) + (4 Ă· 2) = 3 + 2 = 5. (2 Ă— 3) + (4 Ă· 1) = 6 + 4 = 10. Question 22. Mathematical PRACTICE Make a Plan Find possible unknown values to make the equation true. ( Ă— ) + (Ă· 2) = 15 Answer: Equation that’s true: Explanation: Numbers 1, 2, 3,4, 5, and 6 exactly once in the equation: (?? Ă— ??) + (?? Ă· 2) = 15. =(1 Ă— 5) + (4 Ă· 2) = 5 + 2 = 7. (3 Ă— 2) + (6 Ă· 2) = 6 + 3 = 9. = (4 Ă— 3) + (6 Ă· 2) = 12 + 3 = 15. Question 23. Building on the Essential Question Why is knowing the order of operations important? Answer: The order of operations is important becauseÂ it guarantees that people can all read and solve a problem in the same way. Explanation: The order of operations is a group of rules that tells you the right order in which to solve different parts of a math problem.Â Order of operations is important because it guarantees that people can all read and solve a problem in the same way. ### McGraw Hill My Math Grade 4 Chapter 7 Lesson 7 My Homework Answer Key Practice Find the value of each expression. Question 1. 5 + 9 Ă· 3 = _____________ Answer: The value of 5 + 9 Ă· 3 expression = 8. Explanation: 5 + 9 Ă· 3 = 5 + 3 = 8. Question 2. 46 – (6 Ă— 5) = _______________ Answer: The value of 46 – (6 Ă— 5) expression = 16. Explanation: 46 – (6 Ă— 5) = 46 – 30 = 16. Question 3. (3 + 1) + 27 Ă· 9 = _______________ Answer: The value of (3 + 1) + 27 Ă· 9 expression = 7. Explanation: (3 + 1) + 27 Ă· 9 = (3 + 1) + 3 = 4 + 3 = 7. Question 4. 5 Ă— 5 – 8 = ________________ Answer: The value of 5 Ă— 5 – 8 expression = 17. Explanation: 5 Ă— 5 – 8 = 25 – 8 = 17. Question 5. (4 + 20) Ă· 2 + 6 = ________________ Answer: The value of (4 + 20) Ă· 2 + 6 expression = 18. Explanation: (4 + 20) Ă· 2 + 6 = 24 Ă· 2 + 6 = 12 + 6 = 18. Question 6. 2 Ă— 9 + 14 Ă· 2 = _________________ Answer: The value of 2 Ă— 9 + 14 Ă· 2 expression = 25. Explanation: 2 Ă— 9 + 14 Ă· 2 = 2 Ă— 9 + 7 = 18 + 7 = 25. Problem Solving Question 7. Mathematical PRACTICE Model Math Tami buys two books that cost$14 each. She pays an additional $2 in tax. How much did Tami pay altogether? Answer: Total amount of money Tami pay altogether =$30.

Explanation:
Cost of each book = $14. Number of books = 2. Amount of money she pays an additional in tax =$2.
Total amount of money Tami pay altogether = (Cost of each book Ă— Number of books) + Amount of money she pays an additional in tax
= ($14 Ă— 2) +$2
= $28 +$2
= \$30.

Question 8.
Claudio had 34 toy cars. He lost two at the park. Then he divided the rest of the cars evenly among himself and 3 cousins. How many cars did each child get?
Number of toy cars each child get = 8.

Explanation:
Number of toy cars Claudio had = 34.
Number of toy cars he lost in the park = 2.
Number of people he divided them equally = 4.
Number of toy cars each child get = (Number of toy cars Claudio had – Number of toy cars he lost in the park) Ă· Number of people he divided them equally
= (34 – 2) Ă· 4
= 32 Ă· 4
= 8.

Question 9.
Last week, Jean did two sit-ups on Monday and three sit-ups on Wednesday. This week, Jean did three times as many sit-ups as last week How many sit-ups did Jean do this week?
Number of sit ups Jean did this week = 15.

Explanation:
Number of sit-ups on Monday Jean did = 2.
Number of sit-ups on Wednesday Jean did = 3.
This week, Jean did three times as many sit-ups as last week.
Number of sit ups Jean did this week = 3Â  Ă— (Number of sit-ups on Monday Jean did + Number of sit-ups on Wednesday Jean did)
= 3 Ă— (2 + 3)
= 3 Ă— 5
= 15.

Test Practice
Question 10.
Which expression has a value of 20?
(A) 2 Ă— 5 + 5
(B) 3 Ă— (5 + 5)
(C) 3 Ă— 7 – 1
(D) 40 Ă· 5 – 3