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Mathematics

Grade 5

Ordinary and decimal fractions

Module 46

Recognise and classify ordinary fractions

Activity 1:

To recognise and classify ordinary fractions in order to compare them [lo 1.3.2]

RELATIONSHIP SIGNS (<;>; =)

1. Compare the following fractions and then fill in<,>or =.

1.1 3 5 size 12{ { { size 8{3} } over { size 8{5} } } } {} ____ 7 10 size 12{ { { size 8{7} } over { size 8{"10"} } } } {}

1.2 1 3 size 12{ { { size 8{1} } over { size 8{3} } } } {} ____ 1 4 size 12{ { { size 8{1} } over { size 8{4} } } } {}

1.3 5 8 size 12{ { { size 8{5} } over { size 8{8} } } } {} ____ 1 2 size 12{ { { size 8{1} } over { size 8{2} } } } {}

1.4 1 7 size 12{ { { size 8{1} } over { size 8{7} } } } {} ____ 1 5 size 12{ { { size 8{1} } over { size 8{5} } } } {}

1.5 3 4 size 12{ { { size 8{3} } over { size 8{4} } } } {} ____ 6 8 size 12{ { { size 8{6} } over { size 8{8} } } } {}

1.6 3 8 size 12{ { { size 8{3} } over { size 8{8} } } } {} ____ 1 2 size 12{ { { size 8{1} } over { size 8{2} } } } {}

1.7 3 4 size 12{ { { size 8{3} } over { size 8{4} } } } {} ____ 9 12 size 12{ { { size 8{9} } over { size 8{"12"} } } } {}

1.8 3 5 size 12{ { { size 8{3} } over { size 8{5} } } } {} ____ 7 10 size 12{ { { size 8{7} } over { size 8{"10"} } } } {}

1.9 2 11 size 12{ { { size 8{2} } over { size 8{"11"} } } } {} ____ 1 12 size 12{ { { size 8{1} } over { size 8{"12"} } } } {}

1.10 12 12 size 12{ { { size 8{"12"} } over { size 8{"12"} } } } {} ____ 9 9 size 12{ { { size 8{9} } over { size 8{9} } } } {}

2. Compare the following fractions and draw a circle around the one that is the greatest in each of the following:

2.1 1 2 size 12{ { { size 8{1} } over { size 8{2} } } } {} ; 3 4 size 12{ { { size 8{3} } over { size 8{4} } } } {}

2.2 2 3 size 12{ { { size 8{2} } over { size 8{3} } } } {} ; 3 6 size 12{ { { size 8{3} } over { size 8{6} } } } {}

2.3 3 5 size 12{ { { size 8{3} } over { size 8{5} } } } {} ; 9 10 size 12{ { { size 8{9} } over { size 8{"10"} } } } {}

2.4 1 2 size 12{ { { size 8{1} } over { size 8{2} } } } {} ; 2 6 size 12{ { { size 8{2} } over { size 8{6} } } } {}

2.5 3 8 size 12{ { { size 8{3} } over { size 8{8} } } } {} ; 1 2 size 12{ { { size 8{1} } over { size 8{2} } } } {}

2.6 4 5 size 12{ { { size 8{4} } over { size 8{5} } } } {} ; 4 10 size 12{ { { size 8{4} } over { size 8{"10"} } } } {}

Class discussion

HOW can we determine the answers for no. 1 and if we don’t have a diagram to help us?

3. In the following activity you will see how important your knowledge of equivalent fractions is. Once you have mastered it, you will find that it is child’s play to compare the fractions with each other.

Use the rule as determined during your class discussion and fill in<,>or =.

3.1 3 5 size 12{ { { size 8{3} } over { size 8{5} } } } {} ____ 7 15 size 12{ { { size 8{7} } over { size 8{"15"} } } } {}

3.2 7 11 size 12{ { { size 8{7} } over { size 8{"11"} } } } {} ____ 13 22 size 12{ { { size 8{"13"} } over { size 8{"22"} } } } {}

3.3 5 9 size 12{ { { size 8{5} } over { size 8{9} } } } {} ____ 15 27 size 12{ { { size 8{"15"} } over { size 8{"27"} } } } {}

3.4 5 6 size 12{ { { size 8{5} } over { size 8{6} } } } {} ____ 20 24 size 12{ { { size 8{"20"} } over { size 8{"24"} } } } {}

4. Now use your knowledge and fill in<,>or =.

4.1 4 5 size 12{ { { size 8{4} } over { size 8{5} } } } {} ____ 5 6 size 12{ { { size 8{5} } over { size 8{6} } } } {}

4.2 2 3 size 12{ { { size 8{2} } over { size 8{3} } } } {} ____ 4 5 size 12{ { { size 8{4} } over { size 8{5} } } } {}

4.3 5 6 size 12{ { { size 8{5} } over { size 8{6} } } } {} ____ 7 9 size 12{ { { size 8{7} } over { size 8{9} } } } {}

4.4 7 8 size 12{ { { size 8{7} } over { size 8{8} } } } {} ____ 6 7 size 12{ { { size 8{6} } over { size 8{7} } } } {}

To calculate by selecting and using operations [lo 1.8.3]

1. Split up into groups of three. See if you know how to solve the problems.

1.1 Gizelle and her twin brother, Donovan, receive pocket money every month. Gizelle saves two sixths of her pocket money. Donovan saves four ninths of his. Who saves most if they get the same amount of pocket money?

1.2 Mom likes making pancakes. She gives Jake and his friends three quarters to eat. Then Mom makes the same number of pancakes. She sends four fifths of the pancakes to school for Dimitri and his friends to enjoy. Who got the most pancakes from Mom?

1.3 Vusi and Sipho wrote the same test. Vusi answered four sevenths of the questions correctly. Sipho had five eighths right. Who did better in the test?

1.4 Two identical taxis transport passengers between Johannesburg and Pretoria. The one taxi is two thirds full, while the other one is three quarters full. Which taxi transports the most passengers?

Another BRAIN-TEASER!

Arrange the following fractions from biggest to smallest:

2 3 size 12{ { { size 8{2} } over { size 8{3} } } } {} ; 1 2 size 12{ { { size 8{1} } over { size 8{2} } } } {} ; 5 6 size 12{ { { size 8{5} } over { size 8{6} } } } {} ; 7 9 size 12{ { { size 8{7} } over { size 8{9} } } } {}

SIMPLIFYING

Did you know?

In order to write a fraction in its simplest form we divide the numerator and denominator by the same number. The value of the fraction does not change because we are actually dividing the fraction by 1.

E.g. 18 24 size 12{ { {"18"} over {"24"} } } {}
6
 6
= 3 4 size 12{ { {3} over {4} } } {} and 10 15 size 12{ { {"10"} over {"15"} } } {}
5
5
= 2 3 size 12{ { {2} over {3} } } {}

Activity 3:

To simplify common fractions [lo 1.3.2]

1. Now that you know how to simplify a fraction, see whether you can complete the following table:

Fraction ÷ by Simplified
E.g. 18 27 size 12{ { { size 8{"18"} } over { size 8{"27"} } } } {} 9 9 size 12{ { { size 8{9} } over { size 8{9} } } } {} 2 3 size 12{ { { size 8{2} } over { size 8{3} } } } {}
1.1 40 45 size 12{ { { size 8{"40"} } over { size 8{"45"} } } } {} .................. ..................
1.2 15 25 size 12{ { { size 8{"15"} } over { size 8{"25"} } } } {} .................. ..................
1.3 12 16 size 12{ { { size 8{"12"} } over { size 8{"16"} } } } {} .................. ..................
1.4 24 30 size 12{ { { size 8{"24"} } over { size 8{"30"} } } } {} .................. ..................
1.5 48 54 size 12{ { { size 8{"48"} } over { size 8{"54"} } } } {} .................. ..................

Activity 4:

To use a series of techniques to do calculations [lo 1.10.3]

1. In the previous modules you often rounded off whole numbers. Now we are going to round off mixed numbers to the nearest whole number. Connect the number in column A to the correct answer in column B.

Questions & Answers

a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
im not good at math so would this help me
Rachael Reply
how did I we'll learn this
Noor Reply
f(x)= 2|x+5| find f(-6)
Prince Reply
f(n)= 2n + 1
Samantha Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
preparation of nanomaterial
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Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Mathematics grade 5. OpenStax CNX. Sep 23, 2009 Download for free at http://cnx.org/content/col10994/1.3
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