Evaluate from left to right

Transcription

1 Learning Objective We will evaluate numerical expressions involving rational numbers. Students will be able to group symbols dictating the order of applying calculations and how the absence or different placement of these symbols can lead to different results given the same numbers and operations. Use, brackets, or braces in numerical expressions, and evaluate expressions with these symbols. Common Core Standard 7.NS. & 7.NS. Prerequisite Skills Apply and extend previous understandings of addition, subtraction, multiplication, and division of integers (AND other rational numbers); Students will reinforce skills learned in 6 th grade. CFU What are we going to learn? What does evaluate mean? Evaluate means. Make Connect ion Students, you already know how to evaluate simple expressions. Now, we will evaluate numerical expressions that include grouping symbols. Activate Prior Knowledge Evaluate from left to right Vocabular y find the value

2 Concept Developm ent A numerical expression is made up of numbers connected by operations (+,,, ). Grouping Symbols ( ) Evaluating Numerical Expressions Without Grouping Symbols With Grouping Symbols 0 (6 + 8) What is the correct order of operations? CFU 3 + (4 6) To evaluate the numerical expression above, which operation would be calculated first? How do you know? A B 4 6 In your own words, what do grouping symbols mean in a numerical expression? Grouping symbols mean.

3 Skill Development/Guided Practice A numerical expression is made up of numbers connected by operations (+,,, ). Evaluate numerical expressions. Calculate the operation in the grouping symbols. (Evaluate) Continue to evaluate to get a final value. Grouping Symbols ( ). (8 + 36) (36 4) When there are two separate grouping symbols, either one can be evaluated first. 3. (8 + 3) (48 8) 4. (7 9) (63 3) 5. Sunny got $40 from her parents and $60 from her grandparents for her birthday. Sunny saved half of the money. The following are expressions that represents the amount of money that Sunny saved in her piggy bank. 6. Christian bought 3 bags of marbles and Eric bought 5 bags. Each bag has 0 marbles. The following are expressions that represents the number of marbles Christian and Eric bought altogether. ( ) and ( 40) + ( 60) 0 (3 + 5) and (0 3) + (0 5) How much money did Sunny save in her piggy bank? Evaluate both expressions. How many marbles did Christian and Eric buy altogether? Evaluate both expressions. CFU How did I/you know which operation to calculate first?

4 Relevance A numerical expression is made up of numbers connected by operations (+,,, ). Evaluating numerical expressions will help you when purchasing items. Sam s Electronics is having a special on their Blaze music players. What is the total price for 3 music players? (50 3) 0 The total price is $30. Evaluating numerical expressions will help you do well on tests. Sample Test Question: 8. Select the numerical expressions that have a value of 5 when evaluated. Choose Yes or No for A and B. A (0 + 3) 4 O Yes O No B 0 + (3 4) O Yes O No CFU Does anyone else have another reason why it is relevant to evaluate numerical expressions? (Pair-Share) Why is it relevant to evaluate numerical expressions? You may give one of my reasons or one of your own. Which reason is more relevant to you? Why?

5 A numerical expression is made up of numbers connected by operations (+,,, ). Skill Closure Evaluate numerical expressions. Calculate the operation in the grouping symbols. (Evaluate) Continue to evaluate to get a final value. Grouping Symbols ( ). (7 3) 5. (34 + 5) (6 55) Access Common Core Place grouping symbols in the numerical expression so that is calculated first. Then evaluate. How would the value of the expression change if grouping symbols were placed around 5 5 instead? Word Bank evaluate perform Summary Closure What did you learn today about evaluating numerical expressions? (Pair-Share) Use words from the word bank. first

6 Independent Practice A numerical expression is made up of numbers connected by operations (+,,, ). Evaluate numerical expressions. Calculate the operation in the grouping symbols. (Evaluate) Continue to evaluate to get a final value. Grouping Symbols ( ). (56 + 8) 7. (56 7) + (8 7) 3. 9 (50 + 7) 4. (9 60) ( 9 3) 5. Each bottle of water has about 7 fluid ounces (fl oz). Mrs. Garcia brought bottles and Mr. Robison brought 0 bottles for the 5 th grade students volunteering to clean up the local park. The following is an expression to represent the number of fluid ounces of water. 6. Half of the bottles were given to young kids playing in the park. The following is an expression to represent the number of bottles given to the young kids. ( + 0) 7 ( + 0) What is the total amount of water in fluid ounces? How many bottles were given to the young kids?

7 Periodic Review. (3 + 0) 4. (30 7) (54 6) 3. (4 ½) + (4 ½) Access Common Core. Decide if the value of the expression is less than, equal to, or greater than 5. Write a check mark in the correct column. A (0 + 3) 4 B 0 + (3 4) C (40 + ) 4 D Less than 5 Equal to 5 Greater than 5. Decide if the value of the expression is less than, equal to, or greater than 7. Write a check mark in the correct column. A 54 (6 3) B ( 7) (34 + 3) C (54 6) 3 D (9 3) + 5 Less than 7 Equal to 7 Greater than 7

8 Periodic Review. (4 + 36) (77 7). 40 (58 3) 3. (3 ¼) + (40 ¼) Access Common Core Place ( ) in the numerical expression to get the value = = = = = = 85

9 Periodic Review 3. (7 6) + (86 59). (00 ) + (50 ) Access Common Core. Fill in the blanks to create numerical expressions that have a value of 3 when evaluated. 4 4 ( + ) = 3 ( ) = 3 ( 4 ) + ( 4 ) = 3. Fill in the blanks to create numerical expressions that have a value of 4 when evaluated. 7 7 ( + ) = 4 ( ) = 4 ( 7 ) + ( 7 ) = 4