Page 27 - Math Course 1 (Book 1)

Subtracting Integers

Let’s Begin

Subtract a Positive Integer Subtract a Negative Integer

Examples Examples

Find 9 – 14
Find 15 – (–4)
9 - 14 = 9 + (-14) To Subtract 14, add -14
15 - (-4) = 15 + 4 To Subtract -4, add 4.

= -5 Simplify
= 19 Simplify.
-5 Answer 19
Answer

Find –10 – 8 Find –11 – (–7)
-10 - 8 = -10 + (-8) To Subtract 8, add - 8 -11-(-7) = -11 + 7 To Subtract -7, add 7

= -18 Simplify. = -4 Simplify.
-18 -4
Answer Answer

REAL WORLD EXAMPLE
Lowest Highest
State
WEATHER Temperature(0F) Temperature(0F)

The table shows the record high Utah -69 117
and low temperatures recorded in
selected states. Vermont -50 105

What is the range of temperatures Virginia -30 110
for West Virginia?
Washington -48 118

West Virginia -37 112

Explore You know the highest and lowest temperatures. You need to f nd the range for
West Virginia’s temperatures.
Plan To f nd the range, or difference, subtract the lowest temperature from the highest
temperature.
Solve 112 – (–37) = 112 + 37 To Subtract -37 add 37.

= 149 Add 112 and 37.

The range for West Virginia is 149°F.
Answer

19