9
Fractions
Halves, quarters, eighths, tenths I am learning to identify halves, quarters, eighths and tenths. Fractions are made when something (e.g. a number, set or a shape) is divided into equal parts. This rectangle is divided into eight equal parts. Three parts are coloured red. 3 _ are coloured red. 8 We can write fractions using words and digits. one half =
1 _ 2
one quarter =
Each part of the fraction has a name: The number above the line is the numerator. This tells us the number of parts.
1 _ 4
one eighth =
3 _ 8
An enumerator is a person who counts things e.g. answers in a census or votes in an election.
1 _ 8
one tenth =
1 __ 10
The number below the line is the denominator. This tells us the name of the parts, e.g. halves, quarters, eighths, tenths. It also tells the number of equal parts into which the whole has been divided.
Nom is the French for ‘name’. If you nominate someone, you name them for a certain job or task. Ready to go activity 3.8
1 What fraction of each shape is (i) red and (ii) yellow? (a) (b) (c)
(d)
(e)
(h)
(f ) (g)
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2 Talk Time Do any parts in Question 1 have more than one correct answer? Which ones? Why? Strand Number Strand unit/Element Fractions Objectives/Learning outcomes Express one number as a fraction of another number. l Calculate a number, given a multiple fraction of the number. l Solve and complete practical tasks and problems involving fractions. l Identify fractions and equivalent forms of fractions with denominators 2, 3, 4, 5, 6, 8, 9, 10 and 12. l Compare and order fractions with appropriate denominators and position on the number line. l Calculate a fraction of a set using concrete materials. l
Digital resources for this chapter l Ready to go activity 3.8: Use the Fractions e-Manipulative to randomise numerators and denominators (for use on this page) l Create activities: Use the Fractions and Bar Modelling e-Manipulatives at relevant points of the chapter l Ready to go activity 4.7: Fractions e-Manipulative l Write – Hide – Show video 4.3 l Ready to go activity 4.8: Fractions e-Manipulative
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9
Fractions
Work It Out! Draw pictures to represent these problems and then solve them. (a) If you eat one quarter of a cake, what fraction do you have left? (b) If you eat
3 _ 8
of a bar of chocolate, what fraction do you have left?
(c) Pete cut up his pizza into eight equal slices, and started eating them. Now he has only three slices left. What fraction of the pizza has he eaten so far? (d) Daddy cut a block of ice cream into 10 equal slices. If he gave a slice to each of his three children, what fraction of the block of ice cream is left? (e) Jane ate half of her sandwich at first break, and then one quarter of the sandwich at second break. What fraction of the sandwich was left? (f ) Kevin cut up a Swiss roll into 10 equal slices. He gave a slice to the six members of his family, including himself. What fraction of the Swiss roll is gone and what fraction is left?
Other fractions I am learning to identify thirds, fifths, sixths, ninths and twelfths. Dividing into equal parts always creates fractions. This pentagon is divided into five equal parts.
This equilateral triangle is divided into three equal parts.
It is divided into fifths. 2 _ are blue; 35_ are yellow. 5
It is divided into thirds. 1 _ is red; 23_ are green. 3
Sixths
3 _ 6
are red;
Ninths
3 _ 6
are blue.
3 _ 9
are green,
Twelfths
6 _ 9
are yellow.
3 __ 12
are yellow;
9 __ 12
are red. 40
64
Fractions
1 Use cubes to help you to solve these. (a) Put 5 cubes together. What fraction of all of the cubes is (i) 1 cube (ii) 4 cubes? (b) Put 3 cubes together. What fraction of all of the cubes is (i) 1 cube (ii) 2 cubes? (c) Put 12 cubes together. What fraction of of all the cubes is (i) 1 cube (ii) 6 cubes? (d) Put 9 cubes together. What fraction of all of the cubes is (i) 1 cube (ii) 3 cubes? (e) Put 6 cubes together. What fraction of all of the cubes is (i) 1 cube (ii) 4 cubes? 2 What fraction of each shape is (i) coloured and (ii) uncoloured? (a)
(b)
(c)
(d)
(f )
(g)
(h)
(e)
(i) (j) (k) (l)
3 Talk Time
(a) Do any parts in Question 1 or Question 2 have more than one correct answer? Which ones? Why?
(b) Imagine if the shapes above were all coloured in; say what fraction would be coloured in each one, e.g. (a) All coloured is 66_ . 4 In your copy, identify the fractions marked by letters on the number line. A 0
B
1 – 9
2– 3
G 0
D
C
1 – 6
E 1
1
H
I 1
2
1 –3 J
5 –– 12
F
K
L
3
5
–– 112
1–6
2
5 Compare the number lines to identify a fraction equal to: (a) 13_
(b) 123_
(c)
4 __ 12
8 __ (d) 1 12
(e)
4 _ 6
(f) 169_ 65
9
Fractions
Work It Out! Draw pictures to represent these problems and then solve them. (a) Jill ate 13_ of her roll at first break. What fraction of her roll is left? (b) A bar of chocolate has 12 squares. If five of the squares are eaten, what fraction is left? (c) Emily put five cubes together in a line. If three of the cubes are red and the rest are yellow, what fraction of the cubes is yellow? (d) Mike and Emma are playing tic-tac-toe on a square grid with nine small squares. If five of the squares have been written in, what fraction of the square grid is empty? (e) Paul has a large pizza that has been cut into six equal slices. (i) If he eats one slice, what fraction of the pizza will be left? (ii) Paul decides that the slices are too big, so he cuts each slice in half again. What fraction of the whole pizza is each slice now?
Equivalent fractions I am learning to identify equivalent fractions. Equivalent fractions have the same value, but may not look the same. We say, ‘Same value, different appearance’. Create activity
1 Team Work Work with a partner to complete this activity.
You will need: glue, strips of coloured paper (all the same size) and a sheet of backing paper.
(a) Fold a strip of paper to show each of the following: l two equal parts l three equal parts l four equal parts l five equal parts l six equal parts l eight equal parts l nine equal parts l ten equal parts l twelve equal parts. (b) Label each strip with the correct fraction name. (c) Leave one strip unfolded: what does this strip represent? Label this strip. (d) Glue your strips onto a backing sheet with the largest fractions at the top. 66
Digital resources
l
Create activity – Use the Fractions e-Manipulative to practise working with equivalent fractions
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