PURPOSE: To practice adding and subtracting integers with number lines and algebra tiles (charge method). SOL: 7.3 NUMBER LINES

Transcription

1 Name: Date: Block: PURPOSE: To practice adding and subtracting integers with number lines and algebra tiles (charge method). SOL: 7.3 Examples: NUMBER LINES Use the below number lines to model the given ADDITION problems: = (-3) = (-3) = = (-6)=

2 = (-1) = = (-8) = (-5)= = (-1) = =

3 PART TWO Algebra Tiles/Charge Method ADDING SAME SIGNS: Same sign KEEP the sign and ADD Example: = 19 COMBINE Key: = Positive = Negative Directions: Draw tiles onto below mats in order to model given problems (you may use + signs for positives and - signs for negatives: Adding Two Positives: 1. Represent in the mat below. 2. Represent in the mat below = 8 + 3= 3. Represent in the mat below. 4. Represent in the mat below = 4 + 6= 5. What do you notice about all of your above answers? 6. In the space below, write a rule for adding two positive numbers.

4 6. Represent in the mat to the right. Circle the zero pair(s). How many zero pairs are in the problem? What is the solution to ? 7. Represent 2 + (-3) in the mat to the right. Circle the zero pair(s). How many zero pairs are in the problem? What is the solution to 2 + (-3)? 8. Represent in the mat to the right. Circle the zero pair(s). How many zero pairs are in the problem? What is the solution to ? 9. Represent 3 + (-5) in the mat to the right. Circle the zero pair(s). How many zero pairs are in the problem? What is the solution to 3 + (-5)? 10. Why are some answers positive and some answers negative? 11. How can you predict the sign of the sum (answer) before you actually do the math? 12. Write a rule that works for adding integers with different signs.

5 NAME: ADDITION Integer MODELING DATE: / / Represent the following problems on the given number lines: = = = = (-4) = (-4) = (-1) = (-4) = = (-6) =.

6 Algebra Tiles/Charge Method Addition Directions: Draw tiles onto below mats in order to model the given problems : Key: + = Positive - = Negative (-3) = (-4) = = (3) = (-2) = (-6) =

7 Subtraction Modeling Lab Name: Date: PART ONE -- NUMBER LINES Start Examples : 5 8 = -3 End Start 3 (-3) = 6 Use the below number lines to model the given subtraction problems: End = = = = (-6)= (-3) = = 8. 7 (-2) = = (-5) =

8 PART TW0 ALGEBRA TILES / Charge Method Example: 8 6 = 2 Start with 8. Circle what needs to be taken away. What s left? Answer: Put 9 positive tiles on the mat. Take 2 positive tiles away. How many do you have left? Put 7 positive tiles on your mat. Take 5 positive tiles away. How many do you have left? (-3) Put 9 negative tiles on your mat. Take 3 negative tiles away. How many do you have left? (-2) Put 3 negative tiles on your mat. Take 2 negative tiles away. How many do you have left?

9 Subtraction with Zero Pairs : Example: 8-10 = -2 Step One: Step Two: Step Three: NOW, take the 10 away! Do we have 10 positives to take away??... So, we have to add 2 zero pairs in order to make 10 positives! Answer: Put 1 negative tile on your mat. Do you have 2 positive tiles to take away? How can you put 2 positive tiles on your mat without changing the overall value (or charge ) of the mat? How many zero pairs did you add? Take away 2 positive tiles. What do you have left? (This is the answer!) Put 4 negative tiles on your mat. Add zero pairs in order to take away 3 positive tiles. How many zero pairs did you add? What do you have left? Put 7 negative tiles on your mat. Add zero pairs in order to take away 5 positive tiles. How many zero pairs did you add? What do you have left?

10 9. 1 (- 2) Put 1 positive tile on your mat. Add zero pairs in order to take away 2 negative tiles. How many zero pairs did you add? What do you have left? (- 3) Put 4 positive tiles on your mat. Add zero pairs in order to take away 3 negative tiles. How many zero pairs did you add? What do you have left? (-5) Put 7 positive tiles on your mat. Add zero pairs in order to take away 5 negative tiles. How many zero pairs did you add? What do you have left? 12. Why are zero pairs important? 13. Do you need zero pairs to solve the following: -2 (-8)? Use a visual to support your answer. 14. Write a rule that works for subtracting integers.

11 NAME: subtraction INTEGER MODELING DATE: / / Represent the following problems on the given number lines: = = = = (-4) = (-5) = = (-2) = = (-6) =.

12 Algebra Tiles/ Charge Method Subtraction Directions: Draw tiles onto below mats in order to model the given problems. Remember, if you don t have the necessary tiles, you need to ADD zero pairs! Key: + = Positive = - = Negative (-4) = = (-3) = (-2) = =