Slide 2:
EX Use a number line to find the sum.
a. -3 + 6 • Start at -3 End at 3 • -3 + 6 = 3
Slide 3:
EX Use a number line to find the sum.
b. -4 + (-5) • Start at -4 End at -9 • -4 + (-5) = -9
Slide 4:
Rule 1 Adding numbers with the same sign.
To add numbers with the same sign, add and keep the sign.
EX 8 + 7 =
-6 + (-10) = 15 -16
Slide 5:
Rule 2 Adding numbers with different signs.
To add numbers with different signs, subtract and keep the sign of the greater absolute value.
EX -12 + 7 =
18 + (-4)= -5 14
Slide 6:
EX Evaluate 2 + x + - 5 for x = 2. 2 + 2 + -5 4 + -5 -1