6-36th grade math

Subtracting Integers

Objective

• To subtract integers

• Why? Why? You will be able to subtract ANY kind of integer: whole number, fraction, decimal, mixed number!

California State Standards NS 2.3 : Solve … subtraction … problems,

including those arising in concrete situations, that use positive and negative integers …

MR 1.2: Formulate and justify mathematical conjectures based on a general description of the mathematical question of problem posed.

Vocabulary• Negative integers– Integers to the left of zero, on a number line.

Indicates a deficit, to be lower, under, etc.• -2, -0.03, - 50 ¾,

• Inverse operations– Two operations with an opposite effect.

Add/Subtract are inverse operations.• Opposite signs– Pairs of numbers that are the same distance from 0

on a number line. Negatives and Positives are opposite signs.

How to Subtract Integers+7 - ¯2If you have a subtraction

problem, 1) you must do inverse operation AND 2) switch the opposite sign.

To help, circle the integers -circle the first integer, include the sign

AND THEN- circle the subtraction sign and the integer together.

+7 - ¯2+7 + +2 = 9

+7 - ¯2

A subtraction operation with a negative really means add a positive

More Examples

¯4 - ¯6 =

¯4 - ¯6 =¯4 + +6 =+6 + ¯4 = +2

¯5 - ¯4 =

¯5 - ¯4 =

¯5 + +4 =

¯1

¯8 - +6

¯8 - +6 =

¯8 + ¯ 6 =

-14

Try It!

1) ¯3 - +7

2) +1 - ¯8

3) ¯7 - ¯ 7

4) +5 - ¯5

1) ¯3 - +7 = ¯3 + ¯7 =¯102) +1 - ¯8 = +1 + +8 = +93) ¯ 7 - ¯ 7 =¯ 7 + +7 = 04) +5 - ¯5 =+5 + + 5 = +10

Objective Review

• To subtract integers

Why? Why? Now you can subtract ANY kind of integer: whole number, fraction, decimal, mixed number!

Independent Practice

• Complete problems 6-19 and 22

• Copy original problem first.

• Show all work!

• If time, complete Mixed Review: 23-33

• If still more time, work on Accelerated Math.