JSS1: MATHEMATICS  1ST TERM

Whole Numbers I  Week 13 Topics1 Quiz

Whole Numbers II  Week 21 Topic1 Quiz

Counting in Base Two  Week 34 Topics1 Quiz

Arithmetic Operations  Week 43 Topics1 Quiz

Lowest Common Multiple (LCM)  Week 52 Topics1 Quiz

Highest Common Factor  Week 61 Topic1 Quiz

Fraction  Week 77 Topics1 Quiz

Basic Operations with Fractions I  Week 83 Topics1 Quiz

Basic Operations with Fractions II  Week 91 Topic1 Quiz

Directed Numbers  Week 103 Topics1 Quiz

Estimation and Approximation I  Week 113 Topics1 Quiz

Estimation and Approximation II  Week 126 Topics1 Quiz
Conversion of Fractions to Decimals
Topic Content:
 Conversion of Fractions to Decimals
 Worked Examples
Changing Fractions to Decimals:
To express a fraction as a decimal, make an equivalent fraction with a denominator that is a power of ten.
Worked Example 7.5.1:
Express\(\frac {3}{5} \)as a decimal.
Solution:
\( \frac {3}{5} = \frac {3}{5} \: \times \: \frac {10}{10}\\ = \frac {30}{50} \\= \frac {6}{10}\\ = \scriptsize 0.6 \)Note: 5 in 30 gives 6 and 5 in 50 gives 10.
Worked Example 7.5.2:
Express \( \frac {6}{25}\)as a decimal
Solution:
To make the denominator in power of 10 we multiply the numerator and denominator it by 4 to get 100. We are looking for the number that will multiply 25 to get 100.
Note: We can also obtain the number by dividing 100 by 25
⇒ \( \frac {100}{25} \scriptsize = 4 \)
Hence
⇒ \( \frac {6}{25} \\= \frac {6 \: \times \: 4}{25 \: \times \: 4} \\= \frac {24}{100} \\ = \scriptsize 0.24\)
Worked Example 7.5.3:
Express\( \frac {5}{8}\)as a decimal.
Solution
\( \frac {5}{8} \\ = \frac {5 \: \times \: 1000}{8 \: \times \: 1000} \\= \frac {5000}{8000} \\ = \frac {625}{1000} \\ \scriptsize = 0.625\)Ans = 0.625
Hint: To make 8000 to the power of 10 we divide it by 8. i.e 8000 ÷ 8 = 1000 and 5000 ÷ 8 = 625. It is easier to divide with the power of ten as the denominator which in this case is 1000.