### Present Remotely

Send the link below via email or IM

CopyPresent to your audience

Start remote presentation- Invited audience members
**will follow you**as you navigate and present - People invited to a presentation
**do not need a Prezi account** - This link expires
**10 minutes**after you close the presentation - A maximum of
**30 users**can follow your presentation - Learn more about this feature in our knowledge base article

# Fractions and Decimals.

How to add, subtract, multiply and divide fractions and decimals.

How to add fractions:

Step 1: You have to make sure the denominators are the same number.

If the denominators are not the same then there's two ways to make them the same.

* You can find the least common multiple of the denominators.

For Example,

The fraction 2/5 + 1/8 have different denominators so you need to find the multiples of 5 and 8.

The multiples of 5 are: 5, 10, 15, 20, 25, 30, 35, 40

The multiples of 8 are: 8, 16, 24, 32, 40

So the least common multiple is 40.

So you would end up with 16/40 + 5/40

OR

* You can multiply the top and bottom of each fraction by the denominator of the other fraction.

For Example,

2/5 + 1/8

Step 2: Add the top numbers ( Numerators ) and put the answer over the denominator.

For Example,

16/40 + 5/40 = 21/40 How to subtract fractions:

Step 1: You have to make sure that the denominators are the same number.

If the denominators are not the same then there's two ways to make them the same.

* You can find the least common multiples of the denominators.

For Example,

The fraction 4/5 - 3/7 have different denominators so you need to find the multiples of 5 and 7.

The multiples of 5 are: 5, 10, 15, 20, 25, 30, 35

The multiples of 7 are: 7, 14, 21, 28, 35

So the least common multiple is 35.

OR

* You can multiply the top and bottom of each fraction by the denominator of the other fraction.

For Example,

4/5 - 3/7 How to multiply fractions

Step 1: Multiply the top numbers

(numerators)

For example,

1/8 x 3/4 =

You multiply 3 x 1 which is 3.

Step 2:

Multiply the bottom numbers

(denominators)

For example,

1/8 x 3/4 =

You multiply 8 x 4 which is 32.

So your answer would be 3/32.

Step 3: Simplify if needed.

3/32 is already simplified so that's your final answer.

To simplify 21/24 you have to divide the numerator and the denominator by 3.

So your final answer would be 7/8. So you would end up with 28/35 - 15/35

Step 3: Simplify if needed.

For example,

21/40 is already simplified so that's your final answer.

To simplify 6/10 you have to divide the numerator and the denominator by 2.

So your final answer would be 3/5.

Step 2: Add the top numbers (Numerators) and put the answer over the denominator.

For Example,

28/35 - 15/35 = 13/35

Step 3: Simplify if needed.

For example,

13/35 is already simplified so that's your final answer.

To simplify 8/10 you have to divide the numerator and the denominator by 2.

So your final answer would be 4/5. How to divide fractions

Step 1: turn the second fraction upside-down (do the reciprocal)

For example,

5/8 divided by 1/6

1/6 becoms 6/1

Step 2: Multiply the first fraction by the reciprocal; multiply across.

For example,

5/8 x 6/1 =

You multiply 5 x 6 and 8 x 1.

So your answer would be 30/8.

Step 3: Simplify if needed.

to simplify 30/8 you have to divide the denominator by the numerator.

So your answer would be 3.75. Decimals Fractions How to subtract decimals

Step 1: Line up the decimals

For example,

2 . 5 3 1

- 1 . 2 0 5

Step 2: Subtract them.

For example,

2 . 5 3 1

- 1 . 2 0 5

1 . 3 2 5 How to add decimals

Step 1: Line up the Decimals.

For example,

1 . 4 5 2

+ 1 . 3 2 1

Step 2: Add them together.

For example,

1 . 4 5 2

+ 1 . 3 2 1

2 . 7 7 2 10 2 How to multiply decimals

Step 1: Multiply normally, and ignore the decimal points.

Step 2: Put the decimal point in the answer, it will have as many decimal places as the two original numbers combined. You start from the right.

For example,

1.5

x 3.2

3 0

4 5 0

4. 8 0 1 How to divide decimals.

Step 1: Divide normally and ignore the decimal point.

Step 2: Put the decimal point in the same spot as the divident. (slide it up)

For example,

.5

5 2.5 2 1 = 1 2Full transcript

by

Tweet## Maria Marin

on 28 May 2013#### Transcript of Fractions and Decimals.

How to add fractions:

Step 1: You have to make sure the denominators are the same number.

If the denominators are not the same then there's two ways to make them the same.

* You can find the least common multiple of the denominators.

For Example,

The fraction 2/5 + 1/8 have different denominators so you need to find the multiples of 5 and 8.

The multiples of 5 are: 5, 10, 15, 20, 25, 30, 35, 40

The multiples of 8 are: 8, 16, 24, 32, 40

So the least common multiple is 40.

So you would end up with 16/40 + 5/40

OR

* You can multiply the top and bottom of each fraction by the denominator of the other fraction.

For Example,

2/5 + 1/8

Step 2: Add the top numbers ( Numerators ) and put the answer over the denominator.

For Example,

16/40 + 5/40 = 21/40 How to subtract fractions:

Step 1: You have to make sure that the denominators are the same number.

If the denominators are not the same then there's two ways to make them the same.

* You can find the least common multiples of the denominators.

For Example,

The fraction 4/5 - 3/7 have different denominators so you need to find the multiples of 5 and 7.

The multiples of 5 are: 5, 10, 15, 20, 25, 30, 35

The multiples of 7 are: 7, 14, 21, 28, 35

So the least common multiple is 35.

OR

* You can multiply the top and bottom of each fraction by the denominator of the other fraction.

For Example,

4/5 - 3/7 How to multiply fractions

Step 1: Multiply the top numbers

(numerators)

For example,

1/8 x 3/4 =

You multiply 3 x 1 which is 3.

Step 2:

Multiply the bottom numbers

(denominators)

For example,

1/8 x 3/4 =

You multiply 8 x 4 which is 32.

So your answer would be 3/32.

Step 3: Simplify if needed.

3/32 is already simplified so that's your final answer.

To simplify 21/24 you have to divide the numerator and the denominator by 3.

So your final answer would be 7/8. So you would end up with 28/35 - 15/35

Step 3: Simplify if needed.

For example,

21/40 is already simplified so that's your final answer.

To simplify 6/10 you have to divide the numerator and the denominator by 2.

So your final answer would be 3/5.

Step 2: Add the top numbers (Numerators) and put the answer over the denominator.

For Example,

28/35 - 15/35 = 13/35

Step 3: Simplify if needed.

For example,

13/35 is already simplified so that's your final answer.

To simplify 8/10 you have to divide the numerator and the denominator by 2.

So your final answer would be 4/5. How to divide fractions

Step 1: turn the second fraction upside-down (do the reciprocal)

For example,

5/8 divided by 1/6

1/6 becoms 6/1

Step 2: Multiply the first fraction by the reciprocal; multiply across.

For example,

5/8 x 6/1 =

You multiply 5 x 6 and 8 x 1.

So your answer would be 30/8.

Step 3: Simplify if needed.

to simplify 30/8 you have to divide the denominator by the numerator.

So your answer would be 3.75. Decimals Fractions How to subtract decimals

Step 1: Line up the decimals

For example,

2 . 5 3 1

- 1 . 2 0 5

Step 2: Subtract them.

For example,

2 . 5 3 1

- 1 . 2 0 5

1 . 3 2 5 How to add decimals

Step 1: Line up the Decimals.

For example,

1 . 4 5 2

+ 1 . 3 2 1

Step 2: Add them together.

For example,

1 . 4 5 2

+ 1 . 3 2 1

2 . 7 7 2 10 2 How to multiply decimals

Step 1: Multiply normally, and ignore the decimal points.

Step 2: Put the decimal point in the answer, it will have as many decimal places as the two original numbers combined. You start from the right.

For example,

1.5

x 3.2

3 0

4 5 0

4. 8 0 1 How to divide decimals.

Step 1: Divide normally and ignore the decimal point.

Step 2: Put the decimal point in the same spot as the divident. (slide it up)

For example,

.5

5 2.5 2 1 = 1 2