1
What fraction is red?
Discover Mathematics P2: Term 2, Lessons 101–110
GoalName the fraction of a group that has one special kind of object, such as red apples.
New words
group · a set of things togethertotal · all the things in the groupfraction of a group · the part we ask about, over the total
Explanation
A fraction can tell how much of a group is one kind. Count all the things in the group. That number goes on the bottom. Then count the things you are asking about, such as the red apples. That number goes on the top. A basket has 3 red apples and 1 banana. There are 4 pieces of fruit in all. 3 of the 4 are apples, so 3/4 of the fruit are red apples and 1/4 is a banana.
Worked examples
Basket: 2 apples and 2 bananas. There are 4 pieces of fruit in all. 2 are apples, so 2/4 of the fruit are apples. This is the same as 1/2.
Basket: 1 apple and 2 bananas. There are 3 pieces of fruit. 2 are bananas, so 2/3 of the fruit are bananas and 1/3 is an apple.
Basket: 1 apple and 3 bananas. There are 4 pieces in all. 3 are bananas, so 3/4 are bananas.
Class activity
Fruit basket game. Put 4 pieces of fruit or toys of two kinds in a bag, for example 3 toy cars and 1 ball. The child takes them out, counts all of them, counts the cars and says the fraction. Try again with 2 cars and 2 balls, then with 1 and 2 in a bag of 3.
Practice
1
What fraction of the things are balls?
There are 4 things and 3 are balls: 3/4.
2
What fraction of the fruit are apples?
There are 3 pieces of fruit and 2 are apples: 2/3.
3
A group of 4 children has 1 boy and 3 girls. What fraction are girls?
3/4.
4
There are 2 apples and 2 bananas. What fraction are bananas? Write it with fourths.
2/4, which is the same as 1/2.
5
Draw 4 shapes so that 1/4 of them are circles.
1 circle and 3 other shapes, for example 3 squares.