1. Page 71 MMS grade 7 Subtracting integers with number lines

2. 7 -5 =2.draw a yellow arrow to the right from 0 to 7. Then draw a red arrow facing left from 7, stop after 5 jumps.

3. 5 – (-2)=7 think, how many jumps does it take to get from -2 to 5 ? You are measuring the difference between(-2) and 5.

4. (-9) –(+4) = ? How many jumps between -9 and 4 ?

5. One “cheat” when subtracting is to add the opposite. 7-5 = Both are positive integers so simply subtract. 5-(-2)= you are subtracting a negative number so think add the opposite 5+2 = ? -9 –(-4) You are subtracting a negative number from a negative number. Take the absolute value of each number. -9 becomes 9 and negative 4 becomes 4. add. 9+4

6. Confused ? Try this explaination http://www.youtube.com/watch?v=RDw3Gq-heTw

7. Still a little unsure ? Try this. Put a number line on the floor with masking tape. Start at 0 and face in the positive direction. To find (-2)+(+3)= step back 2 steps so you are on -2 on the number line. Now walk ahead three steps.

8. That, now try subtracting. Start was adding the same way but whenever you see a subtraction sign – it means change direction. So turn around To find (+1) –(+3) Stand on 0, face positive direction. Walk forward one step. Now turn around and face the opposite direction and walk forward +3 steps.

9. Let’s try walking on the number and subtracting negative numbers. (-3)-(-5) =? Find zero, face to the positive, walk back ward 3 steps ( backward because it is negative 3) you see a subtraction sign so that means turn around, now go backward 5 steps ( move backwards because 5 is negative) What did you land on ? That is your answer.

10. Please try the following problems. Use a number line or walk them out. Head up you coil note book page. Date subtract integers a) (+7) – (-3) b) (+9) – (-9) c) (+3) – (-7) d) (+5) – (+12) e) (-8) – (-10) f) (-11) - (+13) g) (-15) – (+8) h) (-12) – (-12)