FractionsFractions

Adding and Subtracting Adding and Subtracting

FractionsFractions

Adding Like FractionsAdding Like Fractions

2/4 + 1/4 = 3/42/4 + 1/4 = 3/4

The top number is The top number is called the numeratorcalled the numerator

The bottom number is The bottom number is called the denominatorcalled the denominator

Like fractions mean Like fractions mean that the denominator that the denominator is the sameis the same

When adding like When adding like fractions keep the fractions keep the denominator the same denominator the same and add the numeratorand add the numerator

Adding Like Fractions continuedAdding Like Fractions continued

Lets try what we Lets try what we just learnedjust learned

3/8 +1/8 =3/8 +1/8 = 4/84/8 4/8 can be reduced 4/8 can be reduced

to 1/2to 1/2

Subtracting Like FractionsSubtracting Like Fractions

Subtracting works like Subtracting works like additionaddition

6/10 – 3/10 =6/10 – 3/10 = Remember the Remember the

denominator stays the denominator stays the same, only subtract same, only subtract the numeratorthe numerator

6 – 3 = 36 – 3 = 3 So what is our So what is our

answer ?answer ? 3/103/10

Now it’s time for the real starsNow it’s time for the real stars

Do you think you know all about fractions?

Adding Unlike Fractions Adding Unlike Fractions

We know how to add like fractionsWe know how to add like fractions What do we do if we have fractions What do we do if we have fractions

with different denominators?with different denominators? 7/10 + 1/5 =7/10 + 1/5 = We have to make them like fractionsWe have to make them like fractions The denominator of 1/5 can be The denominator of 1/5 can be

multiplied by 2 to make it 10. multiplied by 2 to make it 10. However, whatever we do to the However, whatever we do to the denominator we must do to the denominator we must do to the numerator.numerator.

Unlike Fractions ContinuedUnlike Fractions Continued

So we multiply the So we multiply the denominator by 2denominator by 2

We also multiply We also multiply the numerator by 2the numerator by 2

1/5 ---1/5 --- 1x2=2 1x2=2 5x2=105x2=10 2/102/10 2/10+7/10= 9/102/10+7/10= 9/10

Subtract Unlike FractionsSubtract Unlike Fractions

11/12 – 2/4 = 11/12 – 2/4 = Let’s get to workLet’s get to work If we multiply 4 by If we multiply 4 by

3 then we get 123 then we get 12 Whatever we do to Whatever we do to

the denominator the denominator we must do to the we must do to the numerator numerator

Multiply 2x3=6Multiply 2x3=6 We get 6/12We get 6/12