Fraction

Fractions

Chapter 9 (page75)

Numerator and Denominator

A fraction shows a part of a whole that is cut into equal parts.

 $\frac{2}{5}$  

In a fraction, the numerator is the number above the line. The denominator is the number below the line.

Equivalent Fractions

Finding equivalent fractions

Rita, Tom and Ari, each have a similar Swiss roll.

Rita cut her Swiss into 2 equal parts and ate 1 part.

Tom cut his Swiss into 4 equal parts and ate 2 parts.

Ari cut his Swiss into 8 equal parts and ate 4 parts.

We can also use diagrams to show the parts that were eaten by the three children.

We can all see that the parts that were eaten by all three children are of the same length. So, the fractions  $\frac{1}{2},\ \frac{2}{4}$ and  $\frac{4}{8}$  are equal. We call them equivalent fractions.

Equivalent fractions are fractions that have different numerators and denominators but with the same value.

Open Ended

Can you write some fractions that are equivalent to

 $\frac{2}{3}$  ?

Open Ended

Can you write some fractions that are equivalent to

 $\frac{8}{12}?$  

Finding Fractions in their Simplest Form

Let us find some fractions that are equivalent to  $\frac{6}{12}$  which have smaller numerators and denominators.

We get the simplest form of a fraction when we cannot divide the numerator and denominator further by any common number,

except 1.

page 79

Comparing and Ordering Fractions

Fractions with common numerators or denominators

(page 80)

There are two similar pizzas.

Different fractions of each pizza were eaten.

Multiple Choice

Which is greater fraction?

•  $\frac{2}{6}$  

•  $\frac{4}{6}$  

When comparing fractions with a common denominator, the fraction with the greater numerator is the greater fraction.

Rita has a piece of cloth. She used 2/10 of it to make Scarf A, 5/10 of it to make Scarf B and 3/10 of it to make Scarf C.

Multiple Choice

Which scarf used the greatest amount of cloth?

• A

• B

• C

Multiple Choice

Which scarf used the least amount of cloth?

• A

• B

• C

Tom ate 4/7 of a cherry pie. Ari ate 4/9 of a similar cherry pie. The pictures show the amount of pie Tom and Ari ate.

Multiple Choice

Who ate more?

• Tom

• Ari

When comparing fractions with a common numerator, the fraction with the smaller denominator is the greater fraction.

Terry had a loaf of bread. He gave 2/5 of it to John, 2/10 of it to William and 2/8 of it to Linda.

Multiple Choice

Who received the biggest piece of bread?

• John

• William

• Linda

Fractions with different numerators and denominators

Which fraction is greater, 2/3 or 5/9?

We can compare these two fractions by finding a fraction equivalent to 2/3 that shares a common denominator with 5/9.

Multiple Choice

Which fraction is greater?

•  $\frac{2}{3}$  

•  $\frac{5}{9}$  

Multiple Choice

Which fraction is smaller?

•  $\frac{2}{5}$  

•  $\frac{1}{2}$  

Nancy used three similar rolls of ribbon to tie some presents. After she used them, Roll A had 4/6 of the ribbon left, Roll B had 1/3 of the ribbon left and Roll C had 2/4 of the ribbon left. Which roll of ribbon had the greatest amount of ribbon left?

To compare the different amounts of ribbon left, we have to find fractions that are equivalent to each of the three fractions and which share a common denominator.

Multiple Choice

Which roll of ribbon had the greatest amount of ribbon left?

• $Roll\ A\ =\ \frac{4}{6}$

• $Roll\ B\ =\ \frac{1}{3}$

• $Roll\ C\ =\ \frac{2}{4}$

page 83

Fraction of a quantity

Min buys 3 bell peppers. 1 out of the 3 bell peppers is yellow.

We can say that 1/3 of the bell peppers is yellow.

Rita buys 9 bell peppers. She divides them into 3 equal groups. 1 out of 3 groups of the bell peppers is yellow.

Multiple Choice

We can say that ___ of the bell peppers are yellow.

• $\frac{1}{2}$

• $\frac{1}{3}$

• $\frac{3}{10}$

• $\frac{1}{4}$

Look at the buttons. Find the 1/5 of the buttons.

We can find 1/5 of the buttons by putting them into 5 equal groups.

10 divided by 5 is equal to 2.

so, 1/5 of 10 is 2.

Multiple Choice

Let us now find 1/2 of the buttons.

• 1

• 2

• 5

• 10

There were 12 parrots. If 1/4 of the parrots were red, how many red parrots were there?

Multiple Choice

There were 12 parrots. If 1/4 of the parrots were red, how many red parrots were there?

• 3

• 4

• 6

• 12

Multiple Choice

What is 3/7 of 49?

• 14

• 21

• 28

• 35

Tom ate 2/5 of a pineapple. The mass of the pineapple he had left was 450 g. What was the mass of the pineapple at first?

Tom ate 2/5 of a pineapple. The mass of the pineapple he had left was 450 g. What was the mass of the pineapple at first?

Multiple Choice

Tom ate 2/5 of a pineapple. The mass of the pineapple he had left was 450 g. What was the mass of the pineapple at first?

• 150

• 450

• 300

• 750

(page 87)