Subtracting Subtracting INTEGERSINTEGERS

Strategy: Strategy: Using Integer ChipsUsing Integer Chips

Subtracting With Integer ChipsSubtracting With Integer ChipsWith a partner …With a partner … Take a look at the examples on pg. 356 and try to Take a look at the examples on pg. 356 and try to

self-learn how to subtract with integer chipsself-learn how to subtract with integer chips Sample this strategy by creating your own subtraction Sample this strategy by creating your own subtraction

question and solve using the integer chips in front of question and solve using the integer chips in front of you.you.

Hint: Take away zeroHint: Take away zero

models??models??

How do you do this?How do you do this?

Subtracting With Integer ChipsSubtracting With Integer Chips

Now try subtracting the following using Now try subtracting the following using integer chips. Draw your solution and integer chips. Draw your solution and write the equation.write the equation.

a)a)5 – 9 = _____5 – 9 = _____

b)b)-5 – (-1) = _____-5 – (-1) = _____

c)c)6 – (-3) = _____6 – (-3) = _____

Strategy: Strategy: Using Number LinesUsing Number Lines

Subtracting with Number LinesSubtracting with Number Lines

With a partner …With a partner … Try to self-learn how to use number lines to subtract Try to self-learn how to use number lines to subtract

integers. Solve the question provided using the integers. Solve the question provided using the number line.number line.

Hints: Hints: -Use the integer chip strategy to get an -Use the integer chip strategy to get an answer so you can compare with your answer so you can compare with your

number line answer.number line answer.

-Try using the second integer first?-Try using the second integer first?

Subtracting IntegersSubtracting IntegersNumber LinesNumber Lines

How do you subtract integers using a How do you subtract integers using a number line?number line? -2 – 5 = ________-2 – 5 = ________

a)a) Start with the second integer (+5) and mark it off on Start with the second integer (+5) and mark it off on the number linethe number line

b)b) Mark off the first integer (-2)Mark off the first integer (-2)

c)c) The difference between the two is your answer. The The difference between the two is your answer. The direction along the number line determines the sign direction along the number line determines the sign (left (-), right (+))(left (-), right (+))

Subtracting IntegersSubtracting IntegersInteger Chips & Number LinesInteger Chips & Number Lines

Now try these questions using number Now try these questions using number lines to solve.lines to solve.

a)a)3 – 7 = _____3 – 7 = _____

b)b)3 – (-2) = _____3 – (-2) = _____

c)c)-4 – (-2) = _____-4 – (-2) = _____

Strategy: Strategy: Solving Mentally (Rules)Solving Mentally (Rules)

Subtracting IntegersSubtracting IntegersUsing Rules to SolveUsing Rules to Solve

With a partner, take a look at these With a partner, take a look at these examples.examples.

What is happening? Can you come up What is happening? Can you come up with a rule?with a rule?

a) 3 – (-2) = 3 + 2 = 5

b) -4 – (-2) = -4 + 2 = -2

c) -3 – 5 = -3 + (-5) = -8

d) 2 – 7 = 2 + (-7) = -5

Subtracting IntegersSubtracting IntegersUsing Rules to SolveUsing Rules to Solve

Subtraction of integers can be done mentally by Subtraction of integers can be done mentally by adding adding the opposite integerthe opposite integer. Then use the rules for adding . Then use the rules for adding integers.integers.

Now try the same questions as before, but using the Now try the same questions as before, but using the rules to solve (show your work).rules to solve (show your work).

a)a) 3 – 7 = _____3 – 7 = _____

b)b) 3 – (-2) = _____3 – (-2) = _____

c)c) -4 – (-2) = _____-4 – (-2) = _____