Understanding Parentheses in Expressions

1. Learning ObjectiveName _______________________ Today, we will use parentheses in expressions. CFU What are we going to do today? Activate (or provide) Prior Knowledge An expression is a mathematical phrase that contains numbers connected by operations1. 1 addition, subtraction, multiplication, division Evaluate2 the following expressions. 2 find the value of • What is the value of 7 × 5 – 3? • What is the value of 6 × 4 – 2? 32 – 3 = 35 – 2 = 22 24 CFU Teacher completes problem 1; students complete problem 2. Students, you already know how to evaluate expressions. Today, we will interpret expressions that use parentheses. 4th Grade Algebra & Functions 1.3 (3Q) Use parentheses to indicate which operation to perform first when writing expressions containing more than two terms and different operations. Lesson to be used by EDI-trained teachers only.

2. Concept Development Example: Reading expressions (7 × 3) + 4 “The value of … seven times three… plus four.” Example: Evaluating expressions (4 × 3) + 8 12 + 8 20 4 × (3 + 8) 4 × 11 44 Parentheses are a rounded pair of symbols ( ) used in an expression to show which part to evaluate first. • When we read an expression inside parentheses, we say “the value of.” • Parentheses affect the order an expression is evaluated in, so often the result is different depending on the location of the parentheses. CFU How would you read this expression? (9 – 4) × 2 20 – (4 × 2). Look at the expression: Which part would you evaluate first? How do you know? A. 20 – 4 B. 4 × 2 In your own words, how do parentheses affect how an expression gets evaluated? Parentheses affect how an expression gets evaluated by __________. Not an example of correct use of parentheses: 8 + 4 × 3 12 × 3 36 4th Grade Algebra & Functions 1.3 (3Q) Use parentheses to indicate which operation to perform first when writing expressions containing more than two terms and different operations. Lesson to be used by EDI-trained teachers only.

3. Skill Development/Guided Practice Name _____________________ Parentheses are a rounded pair of symbols ( ) used in an expression to show which part to evaluate first. Use parentheses in expressions 3check to be sure it is true The expression (5 + 4) × 3 has the parentheses in correct place. 7 + 3 × 5 7 + 3 × 5 1. 5 + 4 × 3 is 27 5 + 4 × 3 5 + 4 × 3 2. 7 + 3 × 5 is 50 The expression (7 + 3) × 5 has the parentheses in the correct place ( ) ( ) ( ) 5 + 4 × 3 5 + 4 × 3 ( ) 7 + 3 × 5 7 + 3 × 5 5 + 12 7 + 15 9 × 3 10 × 5 17 22 27 50 The expression 6 × (5 + 3) has the parentheses in the correct place The expression 4 × (3 + 2) has the parentheses in the correct place. 6 × 5 + 3 4 × 3 + 2 4 × 3 + 2 4. 4 × 3 + 2 is 20 6 × 5 + 3 3. 6 × 5 + 3 is 48 ( ) ( ) ( ) ( ) 6 × 5 + 3 6 × 5 + 3 4 × 3 + 2 4 × 3 + 2 6 × 8 4 × 5 30 + 3 12 + 2 48 20 33 14 CFU (#4) How did I/you verify which expression was correct? (#5) How did I/you interpret the answer? 4th Grade Algebra & Functions 1.3 (3Q) Use parentheses to indicate which operation to perform first when writing expressions containing more than two terms and different operations. Lesson to be used by EDI-trained teachers only.

4. Importance Parentheses are a rounded pair of symbols ( ) used in an expression to show which part to evaluate first. 1. Using parentheses in expressions can help you solve real-life problems. You go to the movies with three of your friends. Each person buys a $10 ticket and $5 soda. How much did the group pay altogether? 2. Using parentheses in expressions will help you do well on tests. Sample Test Question: 1.Which expression is equal to 21? A B C D CFU Does anyone else have another reason why it is important to interpret expressions that use parentheses? (pair-share) Why is it important to interpret expressions that use parentheses? You may give me one of my reasons or one of your own. Which reason means more to you? Why? 4th Grade Algebra & Functions 1.3 (3Q) Use parentheses to indicate which operation to perform first when writing expressions containing more than two terms and different operations. Lesson to be used by EDI-trained teachers only.

5. Parentheses are a rounded pair of symbols ( ) used in an expression to show which part to evaluate first. Concept Closure Heather evaluated this expression. Did she evaluate the expression properly? How do you know? ______________________________________________________________________________________________________________________________________________ 4 + (6 × 5) 10 × 5 50 Skill Closure Use parentheses in expressions 1. 18 – 2 × 3 is 48 18 – 2 × 3 18 – 2 × 3 2. 16 – 2 × 5 is 6 16 – 2 × 5 16 – 2 × 5 ( ) ( ) 16 – 2 × 5 = 6 16 – 2 × 5 = 6 ( ) ( ) 18 – 2 × 3 18 – 2 × 3 = 48 16 – 10 = 6 14 × 5 = 6 16 × 3 18 – 6 = 48 6 = 6 70 = 6 12 = 48 48 The expression (18 – 2) × 3 = 48 has the parentheses in the correct place The expression 16 – (2 × 5) = 6 has the parentheses in the correct place Summary Closure What did you learn today about using parentheses in expressions? Day 1 ______________________________________________________________________________ Day 2 ______________________________________________________________________________ 4th Grade Algebra & Functions 1.3 (3Q) Use parentheses to indicate which operation to perform first when writing expressions containing more than two terms and different operations. Lesson to be used by EDI-trained teachers only.

6. Independent Practice Name _____________________ Parentheses are a rounded pair of symbols ( ) used in an expression to show which part to evaluate first. Use parentheses in expressions The expression (22 – 2) × 6 has the parentheses in the correct place. The expression (9 – 2) × 3 has the parentheses in the correct place 2. 22 – 2 × 6 is 120 22 – 2 × 6 22 – 2 × 6 1. 9 – 2 × 3 is 21 9 – 2 × 3 9 – 2 × 3 ( ) ( ) ( ) ( ) 9 – 2 × 3 9 – 2 × 3 22 – 2 × 6 22 – 2 × 6 9 – 6 22 – 12 7 × 3 20 × 6 3 21 10 120 The expression 4 × (12 – 5) has the parentheses un the correct place. The expression 6 × (3 + 2) has parentheses in the correct place 6 × 3 + 2 4 × 12 – 5 3. 4 × 12 – 5 is 28 4 × 12 – 5 4. 6 × 3 + 2 is 30 6 × 3 + 2 ( ) ( ) ( ) ( ) 4 × 12 – 5 4 × 12 – 5 6 × 3 + 2 6 × 3 + 2 4 × 7 6 × 5 48 – 5 18 + 2 28 30 43 20 4th Grade Algebra & Functions 1.3 (3Q) Use parentheses to indicate which operation to perform first when writing expressions containing more than two terms and different operations. Lesson to be used by EDI-trained teachers only.

7. Periodic Review 1 Name _____________________ Parentheses are a rounded pair of symbols ( ) used in an expression to show which part to evaluate first. Use parentheses in expressions 1. 4 × 7 + 2 is 36 4 × 7 + 2 4 × 7 + 2 8 + 2 × 7 2. 8 + 2 × 7 is 70 8 + 2 × 7 The expression is 4 × (7 + 2) has the parentheses in the correct place The expression (8 + 2) × 7 has the parentheses in the correct place. ( ) ( ) 4 × 7 + 2 4 × 7 + 2 ( ) ( ) 8 + 2 × 7 8 + 2 × 7 4 × 9 8 + 14 28 + 2 10 × 7 36 30 22 70 3. 5 × 14 – 6 is 40 5 × 14 – 6 5 × 14 – 6 4. 4 + 5 × 2 is 18 4 + 5 × 2 4 + 5 × 2 The expression 5 × (14 – 6) has the parentheses in the correct place. The expression (4 + 5) × 2 has parentheses in the correct place. ( ) ( ) ( ) ( ) 5 × 14 – 6 5 × 14 – 6 4 + 5 × 2 4 + 5 × 2 5 × 8 4 + 10 70 – 6 9 × 2 40 14 64 18 4th Grade Algebra & Functions 1.3 (3Q) Use parentheses to indicate which operation to perform first when writing expressions containing more than two terms and different operations. Lesson to be used by EDI-trained teachers only.

8. Periodic Review 2 Name _____________________ Parentheses are a rounded pair of symbols ( ) used in an expression to show which part to evaluate first. Use parentheses in expressions 1. 15 – 7 × 2 is 16 15 – 7 × 2 15 – 7 × 2 2. 18 – 4 × 3 is 6 18 – 4 × 3 18 – 4 × 3 The expression (15 – 7) × 2 has parentheses in the correct place The expression 18 – (4 × 3) has parentheses in the correct place. ( ) ( ) 15 – 7 × 2 15 – 7 × 2 ( ) ( ) 18 – 4 × 3 18 – 4 × 3 15 – 14 18 – 12 8 × 2 14 × 3 1 16 6 42 3. 2 + 9 × 6 is 66 2 + 9 × 6 2 + 9 × 6 4. 30 – 5 × 4 is 10 30 – 5 × 4 30 – 5 × 4 The expression 30 – (5 × 4) has the parentheses in the correct place. The expression (2 + 9) × 6 has the parentheses in the correct place ( ) ( ) ( ) ( ) 2 + 9 × 6 2 + 9 × 6 30 – 5 × 4 30 – 5 × 4 2 + 54 30 – 20 11 × 6 25 × 4 56 10 66 100 4th Grade Algebra & Functions 1.3 (3Q) Use parentheses to indicate which operation to perform first when writing expressions containing more than two terms and different operations. Lesson to be used by EDI-trained teachers only.

9. Periodic Review 3 Name _____________________ Parentheses are a rounded pair of symbols ( ) used in an expression to show which part to evaluate first. Use parentheses in expressions 1. 6 + 10 × 2 is 26 6 + 10 × 2 6 + 10 × 2 2. 12 – 6 × 2 is 0 12 – 6 × 2 12 – 6 × 2 The expression 6 + (10 × 2) has the parentheses in the same place. The expression 12 – (6 × 2) has the parentheses in the correct place. ( ) ( ) 6 + 10 × 2 6 + 10 × 2 ( ) ( ) 12 – 6 × 2 12 – 6 × 2 6 + 20 12 – 12 16 × 2 6 × 2 26 32 0 12 3. 2 × 4 + 10 is 18 2 × 4 + 10 2 × 4 + 10 4. 9 × 5 – 3 is 42 9 × 5 – 3 9 × 5 – 3 The expression (2 × 4) + 10 has the parentheses in the correct place. The expression (9 × 5) – 3 has the parentheses in the correct place. ( ) ( ) ( ) ( ) 2 × 4 + 10 2 × 4 + 10 9 × 5 – 3 9 × 5 – 3 2 × 14 9 × 2 8 + 10 45 – 3 28 18 18 42 4th Grade Algebra & Functions 1.3 (3Q) Use parentheses to indicate which operation to perform first when writing expressions containing more than two terms and different operations. Lesson to be used by EDI-trained teachers only.

10. Blank Page 4th Grade Algebra & Functions 1.3 (3Q) Use parentheses to indicate which operation to perform first when writing expressions containing more than two terms and different operations. Lesson to be used by EDI-trained teachers only.