Negative Numbers Adding and Subtracting Adding and Subtracting

Negative Numbers Adding and Subtracting

Adding and Subtracting with Number Lines We’ll begin with these questions: − 6 + 4 = − 2 + 8 = − 3 − 4 = 7 − 8 = • To answer them, find the starting number in each equation, then locate it on your number line. • Now look at the sign immediately to the right of this number. This tells you whether to move right or left from your starting number; + is telling you to go right, up the number line, and − is telling you to move down, to the left. • The second number tells you by how many to move up or down. Let’s go over that again: • Start on the first number. • Move left or right according to the + or – sign which follows. • The third number tells you how many to move.

Adding and Subtracting with Number Lines − 6 + 4 = Begin at − 6 and move 4 places to the right. This takes you to − 2. − 6 + 4 = − 2

Adding and Subtracting with Number Lines − 2 + 8 = Begin at − 2 and move 8 places to the right. This takes you to 6. − 2 + 8 = 6

Adding and Subtracting with Number Lines − 3 − 4 = Begin at − 3 and move 4 places to the left. This takes you to − 7. − 3 − 4 = − 7

Adding and Subtracting with Number Lines 7− 8= Begin at 7 and move 8 places to the left. This takes you to − 1. 7 − 8 = − 1

Your Turn Now, working individually, try these: 1. − 4 + 6 = 2 2. 8 − 10 = − 2 3. − 2 − 7 = − 9 4. 3 − 12 = − 9 5. − 2 + 1 = − 1