7 th grade Mathematics - 5 Order of Operation 7 th grade Mathematics - 5 Order of Operation

Question 1: Solve the following exercise: A.6 B.3 C.9 D.5

Solution: Solve the following exercise: A.6 B.3 C.9 D.5

The order in which we solve a mathematical exercise is very important. Until now we have learned to solve exercises from left to right, with no consideration to the order of operation. Now we will learn the importance of this order of operation and how it affects the exercise’s result. We will solve the following exercise in two methods:

Method 1 – We will solve the exercise from left to right: We got two different results. The correct result is the one received in method 2. Method 2 – First we will do the division operation and then the addition operation:

Rules Rule 1: If there are only addition and subtraction operations (without brackets), the order of operation is from left to right. For example:

Rule 2: If there are only multiplication and division operations (without brackets), the order of operation is from left to right. For example: Rule 3: If there are multiplication and/or division operations with addition and/or subtraction operations (without brackets), the multiplication and/or division operations are done first. For example:

Question 2: Solve the following exercise: A.4 B.12 C.6 D.16

Solution: Solve the following exercise: A.4 B.12 C.6 D.16

Question 3: Solve the following exercise: A.24 B.48 C.30 D.16

Solution: Solve the following exercise: A.24 B.48 C.30 D.16

Question 4: Solve the following exercise: A.12 B.16 C.20 D.24

Solution: Solve the following exercise: A.12 B.16 C.20 D.24

Question 5: Solve the following exercise: A.9 B.16 C.15 D.12

Solution: Solve the following exercise: A.9 B.16 C.15 D.12

Order of Operation with Brackets Order of Operation with Brackets

Question 6: Solve the following exercise: A.17 B.37 C.40 D.21

Solution: Solve the following exercise: A.17 B.37 C.40 D.21

Rule 4: If there are brackets in the exercise, the operations inside the brackets are done before the operations outside the brackets. Examples: If we ignore the brackets, we will get:

Question 7: Solve the following exercise: A.2 B.9 C.6 D.18

Solution: Solve the following exercise: A.2 B.9 C.6 D.18

Question 8: Solve the following exercise: A.28 B.30 C.36 D.20

Solution: Solve the following exercise: A.28 B.30 C.36 D.20

Question 9: Solve the following exercise: A.2 B.4 C.6 D.8

Solution: Solve the following exercise: A.2 B.4 C.6 D.8

Question 10: Solve the following exercise: A.6 B.3 C.1 D.5

Solution: Solve the following exercise: A.6 B.3 C.1 D.5

Order of Operation with Brackets inside Brackets Order of Operation with Brackets inside Brackets

Question 11: Solve the following exercise: A.33 B.18 C.4 D.6

Solution: Solve the following exercise: A.33 B.18 C.4 D.6

Rule 5: If there are brackets inside brackets in the exercise, we start with the innermost pair of brackets first and work outward. For examples:

Question 12: Solve the following exercise: A.1 B.0 C.10 D.20

Solution: Solve the following exercise: A.1 B.0 C.10 D.20

Question 13: Solve the following exercise: A.11 B.8 C.5 D.7

Solution: Solve the following exercise: A.11 B.8 C.5 D.7

Question 14: Solve the following exercise: A.1 B.10 C.6 D.60

Solution: Solve the following exercise: A.1 B.10 C.6 D.60

Question 15: Solve the following exercise: A.2 B.8 C.16 D.4

Solution: Solve the following exercise: A.2 B.8 C.16 D.4

Summary a) If there are only addition and subtraction operations (without brackets), the order of operation is from left to right. b) If there are only multiplication and division operations (without brackets), the order of operation is from left to right. c) If there are multiplication and/or division operations with addition and/or subtraction operations (without brackets), the multiplication and/or division operations are done first. d) If there are brackets in the exercise, the operations inside the brackets are done before the operations outside the brackets. e) If there are brackets inside brackets in the exercise, we start with the innermost pair of brackets first and work outward.

Homework Convert the following words to a mathematic expressions: 1. Add 3 to the product of 2 times Multiply the quotient of 10 divided by 5 by Subtract 4 from the product of 4 times Divide the sum of 5 and 7 by Multiply the difference between 8 and 2 by the sum of 3 and 5.

Solve the following exercises:

Add brackets to convert the following expressions to true expressions:

Add brackets to the following expression so the result will be 13.

Homework Check Question 3: A. B. C. D. Convert the following words to a mathematic expression: Add 3 to the product of 2 times 4

Solution: A. B. C. D. Convert the following words to a mathematic expression: Add 3 to the product of 2 times 4

Question 5: A. B. C. D. Convert the following words to a mathematic expression: Multiply the difference between 8 and 2 by the sum of 3 and 5

Solution: A. B. C. D. Convert the following words to a mathematic expression: Multiply the difference between 8 and 2 by the sum of 3 and 5

Question 13: Add brackets to convert the following expressions to true expressions: A. B. C. D.

Solution: Add brackets to convert the following expressions to true expressions: A. B. C. D.

Question 16: Add brackets to convert the following expressions to true expressions: A. B. C. D.

Solution: Add brackets to convert the following expressions to true expressions: A. B. C. D.