Adding and Subtracting Fractions

Criss-Cross Smiley Face Method

by Mr. Hoover

Click to begin

Adding and Subtracting Positive and Negative Numbers

Signs are the same: add the numbers and keep the sign.

• 2 + 3 = 5• -2 – 3 = -5• -2 + -3 = -5

Signs are opposite: subtract the numbers and take the sign of the larger number.

• 8 – 5 = 3 (8-5 is 3, and the sign of the larger number is positive)• 5 – 8 = -3 (8-5 is 3, and the sign of the larger number is negative)

Click to continue

Skills Review

Skills Review

Multiplying Positive and Negative Numbers

Signs are the same: the sign of the answer will be positive.

• 4 x 5 = 20• -4 x -5 = 20

Signs are opposite: the sign of the answer will be negative.

• 4 x -5 = -20• -4 x 5 = -20

Click to continue

Skills Review Adding, Subtracting, and Multiplying Positive and Negative Numbers

Click on the correct answer.

1. 5 + 2 = 01 2 3 4 5 6 8 9 10

-1 -2 -3 -4 -5 -6 -7 -8 -9 -10

7

Skills Review Adding, Subtracting, and Multiplying Positive and Negative Numbers

Click on the correct answer.

2. 5 – 2 01 2 74 5 6 8 9 10

-1 -2 -3 -4 -5 -6 -7 -8 -9 -10

3

Skills ReviewAdding, Subtracting, and Multiplying Positive and Negative Numbers

Click on the correct answer.

3. - 5 + 2 = 01 2 3 4 5 6 8 9 10

-1 -2

7

-4 -5 -6 -7 -8 -9 -10-3

Skills ReviewAdding, Subtracting, and Multiplying Positive and Negative Numbers

Click on the correct answer.

4. - 5 – 2 = 01 2 74 5 6 8 9 10

-1 -2 -3 -4 -5 -6

3

-8 -9 -10-7

You are correct!

Go on to the next question.

You are correct!

Go on to the next question.

You are correct!

Go on to the next question.

You are correct!

Move on to the next section.

Criss-Cross Smiley Face Method

Click to continue

2 + 3 = 5 4

Step 1: Criss – multiply 2 x 4 and bring down + sign

Step 2: Cross – multiply 3 x 5

Step 3: Smiley Face – multiply 5 x 4Step 4: Solve and simplify if needed. Leave fraction as an improper fraction.

2 x 4

8 + 20 5 x 4

3 x 5

15 23 = 20

Criss-Cross Smiley Face Method

Click to continue

1 - 2 = 6 3

Step 1: Criss – multiply 1 x 3 and bring down - sign

Step 2: Cross – multiply 2 x 6

Step 3: Smiley Face – multiply 6 x 3Step 4: Solve and simplify if needed. Leave fraction as an improper fraction.

1 x 3

3 - 18 6 x 3

2 x 6

12 -9 = = 18

-1

2

Practice

Click on the correct answer.Leave fraction as an improper fraction.

1 + 3 = 5 4

OK, let’s practice what we just learned.

= ?

?

?

?

49

420

199

1920

Practice

Click on the correct answer.Leave fraction as an improper fraction.

2 - 2 = 3 5

= ?

?

?

?

015

4 15

0-2

-415

Practice

Click on the correct answer. Leave fraction as an improper fraction.

6 + 4 = 7 3

= ?

?

?

?

2421

4621

1 1

2410

Practice

Click on the correct answer.Leave fraction as an improper fraction.

7 - 1 = 5 6

= ?

?

?

?

6 11

47 11

37 30

1 5

You are correct!

Go on to the next question.

You are correct!

Go on to the next question.

You are correct!

Go on to the next question.

You are correct! Congratulations!

You have completed the last question!

THE ENDTHE END

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