LC O 6 12 =? 6 + ( 12) = 18. Add the Opposite... Leave Change Opposite. the same... different... Subtraction. Know this Term

Transcription

1 Adding/Subtracting Integers Copy Notes Adding and Subtracting Integers Copy Notes Addition Subtraction the same... Add, and keep the sign... ex = ( 3) = 5 Are the signs... different... Subtract, and keep the sign of the larger absolute value. ex = ( 8) = 3 Know this Term Absolute Value is distance, and distance can NEVER be negative. Add the Opposite... ex. 4 9 = 4 +( 9) = 13 ex. 3 ( 7) = = 10 L C O Leave Change Opposite LC O 6 12 =? 6 + ( 12) = 18

2 Using A Number Line To Add Integers 3 + ( 7) When graphing on a number line, always start at zero and work from there... Also, the first number is always the line closest to the number line and then work up ( 7) = 4 For Example 2 + ( 5) Click 2 + ( 5) = 7

3 Rules For Adding Integers If the signs are the same... find the sum of the two numbers and use the same sign as the integers. Ex. 2 + ( 2) = 4 If the signs are different... find the difference of the two numbers and use the sign of the integer with the greater absolute value. Ex = 0 If The Signs Are The Same ( 6) Notice that the signs are the same. Add the absolute values of the numbers together. And keep the sign that the numbers had originally.

4 If The Signs Are The Same ( 6) Notice that the signs are the same. Add the absolute values of the numbers together. And keep the sign that the numbers had originally. If The Signs Are The Same ( 6) Notice that the signs are the same. Add the absolute values of the numbers together. And keep the sign that the numbers had originally.

5 If The Signs Are The Same ( 12) Notice that the signs are the same. Add the absolute values of the numbers together. And keep the sign that the numbers had originally. If The Signs Are The Same ( 12) Notice that the signs are the same. Add the absolute values of the numbers together. And keep the sign that the numbers had originally.

6 If The Signs Are The Same ( 12) Notice that the signs are the same. Add the absolute values of the numbers together. And keep the sign that the numbers had originally. And When The Signs Are Different Notice the signs are different. Subtract the absolute values of the two numbers. Keep the sign of the larger absolute value. 9

7 And When The Signs Are Different Notice the signs are different. Subtract the absolute values of the two numbers. Keep the sign of the larger absolute value. 9 And When The Signs Are Different Notice the signs are different. Subtract the absolute values of the two numbers. Keep the sign of the larger absolute value. 9

8 And When The Signs Are Different Notice the signs are different. Subtract the absolute values of the two numbers. Keep the sign of the larger absolute value. 17 And When The Signs Are Different Notice the signs are different. Subtract the absolute values of the two numbers. Keep the sign of the larger absolute value. 17

9 And When The Signs Are Different Notice the signs are different. Subtract the absolute values of the two numbers. Keep the sign of the larger absolute value. 17 Practice 8 + ( 17) 27 + ( 23) ( 5)

10 Melanie wants to check her calorie count after breakfast and exercise. Use information from the journal entry to find her total. Use a positive sign for calories and a negative sign for calories burned (-110) + (-40) Monday Morning Calories Oatmeal 145 Toast w/ jam 62 8 oz. juice 111 Calories Burned Walk 6 laps 110 Swam 6 laps 40 Group integers w/ same signs. ( ) + ( ) (-150) 168 Melanie wants to check her calorie count after breakfast and exercise. Use information from the journal entry to find her total. Use a positive sign for calories and a negative sign for calories burned (-110) + (-40) Monday Morning Calories Oatmeal 145 Toast w/ jam 62 8 oz. juice 111 Calories Burned Walk 6 laps 110 Swam 6 laps 40 Group integers w/ same signs. ( ) + ( ) (-150) 168

11 Melanie wants to check her calorie count after breakfast and exercise. Use information from the journal entry to find her total. Use a positive sign for calories and a negative sign for calories burned (-110) + (-40) Monday Morning Calories Oatmeal 145 Toast w/ jam 62 8 oz. juice 111 Calories Burned Walk 6 laps 110 Swam 6 laps 40 Group integers w/ same signs. ( ) + ( ) (-150) 168 Melanie wants to check her calorie count after breakfast and exercise. Use information from the journal entry to find her total. Use a positive sign for calories and a negative sign for calories burned (-110) + (-40) Monday Morning Calories Oatmeal 145 Toast w/ jam 62 8 oz. juice 111 Calories Burned Walk 6 laps 110 Swam 6 laps 40 Group integers w/ same signs. ( ) + ( ) (-150) 168

12 Melanie wants to check her calorie count after breakfast and exercise. Use information from the journal entry to find her total. Use a positive sign for calories and a negative sign for calories burned (-110) + (-40) Monday Morning Calories Oatmeal 145 Toast w/ jam 62 8 oz. juice 111 Calories Burned Walk 6 laps 110 Swam 6 laps 40 Group integers w/ same signs. ( ) + ( ) (-150) 168 You Try..!! On Monday morning, a mechanic has no cars in her shop. The table below shows the number of cars dropped off and picked up each day. Find the total number of cars left in her shop on Friday Day Monday Tuesday Wednesday Thursday Friday Cars Dropped Off Cars Picked Up

13 STAAR Practice STAAR Practice A newspaper gains and loses subscribers daily, as some people subscribe and other people cancel their subscriptions. The table below shows the subscriptions and cancellations for a newspaper during the first two months of the year. Month New Subscriptions Cancellations January February If the newspaper started the year with s subscriptions, which expression can be used to find how many subscriptions the newspaper had at the end of the two month period? F. s ( 30) ( 120) G. s H. s J. s + ( 30) + ( 120)

14 Two things to look for when subtracting integers... Two things to look for when subtracting integers... Is there at least one negative number in the subtraction problem?

15 Two things to look for when subtracting integers... Is there at least one negative number in the subtraction problem? If both numbers are positive, is the number that is being subtracted (the second number) larger than the other number? Subtracting integers is the same as adding its opposite ( 7 ) = 4 4 ( 5 ) Use L C O HINT LEAVE CHANGE OPPOSITE L C O 8 ( 5 ) = 13

16 Extra Practice L C O 6 ( 3 ) 6 + ( 3 ) = L C O ( 3 ) = 14 ( 9 ) = ( 2 ) = = = 3 Evaluate each expression for the given value of the variable. 8 k for k = 6 L C O 8 ( 6 ) = 9 y for y = 4 5 n 6 for n = 2 8

17 o o The temperature rose from -4 F to 45 F in Spearfish, South Dakota on January 22, 1943, in only two minutes. By how many degrees did the temperature change? Click for Answer o 49 A submarine cruising at 27 meters below sea level, or -27 m, descends 14 meters. What is the new depth? - 41 m Click for Answer Be sure to change both the operation symbol and the sign of the second number.

18 STAAR Practice STAAR Practice

19 exit ticket Critical Writing In your own words, describe the process for adding negative numbers together... 1) 6 ( 4 ) 2) 3 3 3) 4 ( 5 ) Lesson Quiz Evaluate each expression for the given value of the variable. 4) 9 s for s = 5 5) 4 w + 5 for w = 21 6) Sam is flying in an airplane, and rises an additional 20 feet. Then he descends 190 feet toward the ground. How far below his original height did Sam go?

20 1) 6 ( 4 ) 2 2) ) 4 ( 5 ) 9 Lesson Quiz Answer Key Evaluate each expression for the given value of the variable. 4) 9 s for s = ) 4 w + 5 for w = ) Sam is flying in an airplane, and rises an additional 20 feet. Then he descends 190 feet toward the ground. How far below his original height did Sam go? 170 feet Homework Workshee t Quiz Monday Practice and Problem Solving

21

22