Subject: Mathematics
Class: JSS 1
Term: First Term
Week: 6
Age: 12 years
Topic: Fractions Continued
Sub-topic: Ordering of Fractions, Conversion of Fractions to Percentages and Vice Versa, Conversion of Fractions to Decimals and Vice Versa
Duration: 40 minutes
Behavioural Objectives
By the end of the lesson, students should be able to:
- Order fractions from smallest to largest.
- Convert fractions to percentages and percentages to fractions.
- Convert fractions to decimals and decimals to fractions.
Keywords
Ordering, Fractions, Percentages, Decimals, Conversion
Set Induction
Begin by discussing how we often compare quantities in everyday life, such as comparing prices or amounts, and relate this to ordering fractions.
Entry Behaviour
Students should be familiar with basic fractions and their operations.
Learning Resources and Materials
- Fraction and decimal charts
- Whiteboard and markers
- Worksheets with conversion exercises
- Calculators
Building Background/Connection to Prior Knowledge
Students should recall how to perform basic fraction operations and understand decimal and percentage concepts.
Embedded Core Skills
- Mathematical reasoning
- Problem-solving
- Numerical fluency
Content
- Ordering of Fractions: Arranging fractions from smallest to largest by comparing their sizes.
- Example: Order 1/4, 2/3, and 5/6.
- To compare fractions, find a common denominator or convert them to decimals.
- Conversion of Fractions to Percentages:
- To convert a fraction to a percentage, multiply the fraction by 100.
- Example: 3/4 = 0.75 × 100 = 75%.
- Conversion of Percentages to Fractions:
- To convert a percentage to a fraction, divide by 100 and simplify.
- Example: 60% = 60/100 = 3/5.
- Conversion of Fractions to Decimals:
- To convert a fraction to a decimal, divide the numerator by the denominator.
- Example: 7/8 = 0.875.
- Conversion of Decimals to Fractions:
- To convert a decimal to a fraction, write the decimal as a fraction with a denominator of 10, 100, etc., and simplify.
- Example: 0.6 = 6/10 = 3/5.
Evaluation
- Order these fractions from smallest to largest: 1/2, 3/4, 2/5.
- Convert the following fractions to percentages: 2/5, 7/10.
- Convert 45% to a fraction.
- Convert 0.25 to a fraction.
- Order these decimals from smallest to largest: 0.4, 0.75, 0.2.
Fractions
1. Ordering of Fractions
To compare fractions, it’s easier if they have the same denominator.
Example 1: Which is larger: 5/7 or 6/8?
Solution:
- Convert to a common denominator:
- 5/7 x 8/8 = 40/56
- 6/8 x 7/7 = 42/56
- 6/8 is larger than 5/7.
Examples:
Example 2: Which has the greater mass: 3054g or 3.56kg?
Solution:
- Convert 3.56kg to grams:
- Compare 3054g and 3560g:
- 3560g is larger than 3054g.
Example 3: Which is larger?
a. 3 21/50 or 3 31/60
b. 37/45 or 19/24
Solution:
a. Convert the fractional parts to a common denominator:
- 21/50 x 6/6 = 126/300
- 31/60 x 5/5 = 155/300
- 3 31/60 is larger than 3 21/50.
b. Convert to a common denominator:
- 37/45 x 8/8 = 296/360
- 19/24 x 15/15 = 285/360
- 37/45 is larger than 19/24.
Example 4: Arrange the following fractions in ascending order: 1/3, 1/9, 5/18, 2/3, 5/6, 7/12, 3/4
Solution:
a. Convert to a common denominator:
- 1/3 = 6/18
- 1/9 = 2/18
- 5/18 is already in the same denominator.
- Ascending order: 1/9, 5/18, 1/3
b. Convert to a common denominator:
- 2/3 = 8/12
- 5/6 = 10/12
- 7/12 is already in the same denominator.
- 3/4 = 9/12
- Ascending order: 7/12, 2/3, 3/4, 5/6
Percentages
- Converting Percentages to Fractions
To convert a percentage to a fraction, divide by 100.
Examples:
i. 30% = 30/100 = 3/10
ii. 75% = 75/100 = 3/4
iii. 7.5% = 7.5/100 = 15/200 = 3/40
iv. 13.75% = 13.75/100 = 55/400 = 11/80
- Converting Percentages to Decimals
To convert a percentage to a decimal, divide by 100.
Examples:
i. 45% = 45/100 = 0.45
ii. 34.75% = 34.75/100 = 0.3475
iii. 5.8% = 5.8/100 = 0.058
- Converting Fractions to Percentages
To convert a fraction to a percentage, multiply by 100.
Examples:
i. 1/4 = 25%
ii. 25/400 = 31.25%
iii. 5/8 = 62.5%
- Converting Decimals to Percentages
To convert a decimal to a percentage, multiply by 100.
Examples:
i. 0.75 = 0.75 x 100 = 75%
ii. 0.045 = 0.045 x 100 = 4.5%
- Finding the Percentage of a Quantity
To find the percentage of a quantity, express the percentage as a fraction and then multiply by the quantity.
Examples:
i. 4.5% of N248 = (4.5/100) x 248 = N11.16
ii. 20% of N250 = (20/100) x 250 = N50
- Expressing One Quantity as a Percentage of Another
To express one quantity as a percentage of another, divide the first quantity by the second and multiply by 100.
Examples:
i. 8 students out of 40 did not do their assignments:
- Percentage: (8/40) x 100 = 20% did not do their assignment.
- Percentage who did their assignment: 80%
ii. What percentage of N5 is 150 kobo?
- Convert N5 to kobo: 500 kobo
- Percentage: (150/500) x 100 = 30%
iii. What percentage of 15 km is 20,000 cm?
- Convert 15 km to cm: 1,500,000 cm
- Percentage: (20,000/1,500,000) x 100 = 1.33%
Converting Fractions to Decimals
- Terminating Decimals
When the denominator divides exactly into the numerator, it results in a terminating decimal.
Example: Change 3/4 to a decimal:
- Recurring Decimals
When converting fractions to decimals results in repeating figures.
Examples:
i. 4/9 = 0.444…
ii. 6/11 = 0.5454…
Convert these decimals to fractions:
i. 0.4 = 4/10 = 2/5
ii. 0.067 = 67/1000
- Addition and Subtraction of Decimals
Examples:
i. 0.6 + 1.7 = 2.3
ii. 0.59 – 0.55 = 0.44
iii. 7.5 + 1.8 = 9.3
iv. 9.3 – 6.2 = 3.1
- Multiplication and Division of Decimals
Examples:
i. 0.08 x 0.7 = 0.056
ii. 0.5 x 7 = 3.5
iii. 0.18 ÷ 1.2 = 0.15
iv. 1.56 ÷ 1.2 = 1.3
Evaluation
- Fractions:
a. Which fraction is larger?
b. Arrange in ascending order:
- 3/5, 8/15, 17/30
- 3/5, 5/8, 7/10, 13/20
- Percentages:
a. Calculate:
- Converting Fractions to Decimals:
a. Convert:
Reading Assignment
- Essential Mathematics for JSS1 by AJS Oluwasanmi, pages 51-56
- New General Mathematics for JSS1 by MF Macrae, pages 31-38
Evaluation: