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JSS2: MATHEMATICS - 1ST TERM

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  1. Properties of Whole Numbers I | Week 1
    4Topics
    |
    2 Quizzes
  2. Properties of Whole Numbers II | Week 2
    4Topics
    |
    2 Quizzes
  3. Properties of Whole Numbers III | Week 3
    4Topics
    |
    1 Quiz
  4. Indices | Week 4
    2Topics
    |
    1 Quiz
  5. Laws of Indices | Week 5
    5Topics
    |
    1 Quiz
  6. Whole Numbers & Decimal Numbers | Week 6
    4Topics
    |
    1 Quiz
  7. Standard Form | Week 7
    3Topics
    |
    1 Quiz
  8. Significant Figures (S.F) | Week 8
    4Topics
    |
    1 Quiz
  9. Fractions, Ratios, Proportions & Percentages I | Week 9
    6Topics
    |
    1 Quiz
  10. Fractions, Ratios, Proportions & Percentages II | Week 10
    4Topics
    |
    1 Quiz
  11. Fractions, Ratios, Proportions & Percentages III | Week 11
    3Topics
    |
    1 Quiz
  12. Approximation & Estimation | Week 12
    1Topic
    |
    1 Quiz
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To express one quantity as a percentage of another, write the first quantity as a fraction of the second and then multiply by 100.

Example 1

a. What percentage of 550g  is 11g?

b. What percentage of 800 is 300?

c. What percentage of ₦2 is 50 kobo?

d. What percentage of 3kg  is 300g

Solution

a. Fraction of the quantity =  \( \frac{11g}{550g} \\ = \frac{1}{50} \)

% of quantity  =  \( \frac{1}{50} \scriptsize \: \times \: 100\% \scriptsize = 20\%\)

b. Fraction of the quantity =  \( \frac{300}{800}= \frac{3}{8} \)

% of quantity  =  \( \frac{3}{8} \scriptsize \: \times \: 100\% \scriptsize = 20\% \\ = \frac{3 \: \times \: 100}{8}\\ = \frac{3 \: \times \: 25}{2} \\ = \frac{75}{2} \\ = \scriptsize 37.5\%\)

c. Fraction of the quantity =  \( \frac{50 \: kobo}{₦2}\)

₦  and kobo are different units.

Convert  ₦ to kobo

₦1 = 100 kobo

₦2  = 100 x 2 =  200 kobo

Fraction of the quantity =  \( \frac{50 \: kobo}{200 \: kobo} \\ = \frac{1}{4}\)

% of quantity  =  \( \frac{1}{4} \scriptsize \: \times \: 100\% \scriptsize = 25\%\)

d. Fraction of the quantity =  \( \frac{300g}{3kg}\)

But g and kg are different units.

Convert kg to g.

1kg  = 1000g

3kg  = 3 x 1000g   =   3000g

Fraction of the quantity =  \( \frac{300g}{3000g} = \frac{3\not{0}\not{0}g}{30\not{0}\not{0}g} \\ = \frac{3}{30} \\ = \frac{1}{10}\)

% of quantity  =  \( \frac{1}{10} \scriptsize \: \times \: 100\%\\ = \scriptsize 10\%\)

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