To compare these values, convert them all to the same format (fraction or decimal).

Without a calculator, it is easier to convert these values to fractions with a common denominator.

Use a denominator of 20, as this is the lowest common multiple of 4, 5 and 20.

Calculate equivalent fractions for each value.

$\begin{array}{rcl} \frac{3}{4} & = & \frac{3 \times 5}{4 \times 5} = \frac{15}{20} \\ 0 & = & \frac{0}{20} \\ - 1 & = & \frac{- 1 \times 20}{1 \times 20} = - \frac{20}{20} \\ - \frac{4}{5} & = & - \frac{4 \times 4}{5 \times 4} = - \frac{16}{20} \end{array}$

Order the values by comparing the numerators.

$\frac{15}{20}, \frac{0}{20}, - \frac{20}{20}, - \frac{17}{20}, - \frac{16}{20} - \frac{20}{20}, - \frac{17}{20}, - \frac{16}{20}, \frac{0}{20}, \frac{15}{20}$

Write answer using the original values.

4 values in correct order when 1 value covered [1]

$- 1, - \frac{17}{20}, - \frac{4}{5}, 0, \frac{3}{4}$ [1]

could be even or odd	always even
always prime	always odd

Number Toolkit (Cambridge O Level Maths)

Exam Questions