Name: _____________________________ Date:_____________ Block: __________ PURPOSE: To practice adding and subtracting integers with number lines and algebra tiles (charge method). SOL: 7.3 NUMBER LINES Examples: Use the below number lines to model the given ADDITION problems: 1. 4 + 3 = _____ 2. 7 + (-3) = _____ 3. -6 + (-3) = _____ 4. -10 + 2 = _____ 5. -2 + (-6)= _____ 6. -4 + 7 = _____ 7. -7 + (-1) = _____ 8. -6 + 8 = _____ 9. 10 + (-8) = _____ 10. 1 + (-5)= _____ 11. -3 + 0 = _____ 12. -9 + (-1) = _____ 13. -3 + 9 = ______ PART TWO – Algebra Tiles/Charge Method ADDING “SAME” SIGNS: Same sign KEEP the sign and ADD Example: 7 + 12 = 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 2 + 5 in the mat below. 2 + 5 = ______ 2. Represent 8 + 3 in the mat below. 8 + 3= ______ 3. Represent 9 + 0 in the mat below. 9 + 0 = ______ 4. Represent 4 + 6 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. 6. Represent -4 + 9 in the mat to the right. Circle the zero pair(s). How many zero pairs are in the problem ? _____ What is the solution to -4 + 9 ? _____ 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 -2 + 8 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 + 8 ? _____ 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. NAME:__________________________ “ADDITION Integer MODELING” DATE: ______/_______/_______ Represent the following problems on the given number lines: 1. -2 + 6 = ……….. 2. -4 + -2 = ………. 3. -5 + 3 = ………. 4. 2 + 5 = ………. 5. 9 + (-4) = ………. 6. -3 + (-4) = ………. 7. -8 + (-1) = ………. 8. 5 + (-4) = ………. 9. 3 + 6 = ………. 10. -1 + (-6) = ………. Algebra Tiles/Charge Method Addition Directions: Draw tiles onto below mats in order to model the given problems : 1. 4 + (-3) = _____ 2. -8 + (-4) = _____ 3. 7 + 5 = _____ 4. -12 + (3) = _____ 5. 9 + (-2) = _____ 6. -7 + (-6) = _____ Key: + = Positive - = Negative Name:_______________________ Date: _______________________ Subtraction Modeling Lab 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: 1. 4 – 3 = _____ 2. 7 – 9 = _____ 3. -6 – 3 = _____ 4. -4 – 2 = _____ 5. -2 – (-6)= _____ 6. -5 – (-3) = _____ 7. 8 – 2 = _____ 8. 7 – (-2) = _____ 9. 4 – 7 = _____ 10. 2 – (-5) = _____ End PART TW0 – ALGEBRA TILES / Charge Method Example: 8 – 6 = 2 1. 9–2 Put 9 positive tiles on the mat. Take 2 positive tiles away. How many do you have left? _______ 2. 7–5 Put 7 positive tiles on your mat. Take 5 positive tiles away. How many do you have left? _______ 3. -9 – (-3) Put 9 negative tiles on your mat. Take 3 negative tiles away. How many do you have left? _______ 4. -3 – (-2) Put 3 negative tiles on your mat. Take 2 negative tiles away. How many do you have left? _______ Start with 8. Circle what needs to be taken away. What’s left? Answer: Subtraction with “Zero Pairs”: Example: 8 -10 = -2 Step One: Step Two: Step Three: NOW, take the 10 away! Answer: Do we have 10 positives to take away?? 6. . . . So, we have to add 2 zero pairs in order to make 10 positives! -1 – 2 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!) 7. -4 – 3 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? ________ 8. -7 – 5 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? _________ 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? _______ 10. 4 – (- 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? ________ 11. 7 – (-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. NAME:__________________________ “subtraction INTEGER MODELING” DATE: ______/_______/_______ Represent the following problems on the given number lines: 1. 6 – 2 = ……….. 2. 3 – 7 = ………. 3. -6 – 3 = ………. 4. -1 – 5 = ………. 5. 2 – (-4) = ………. 6. -2 – (-5) = ………. 7. -8 – 1 = ………. 8. 5 – (-2) = ………. 9. 3 – 6 = ………. 10. -1 – (-6) = ………. 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! 1. 4 – 2 = _____ 2. -8 – (-4) = _____ 3. -8 – 5 = _____ 4. 10 – (-3) = _____ 5. -9 – (-2) = _____ 6. -7 – 9 = _____ Key: + = Positive - = Negative