Equivalent ratios and proportional shares

Equivalent ratios and proportional shares

Secondary 1
TGM Original — E Math Summary Notes (4052), 2026 editorial manuscript

A ratio compares quantities in a stated order. For like quantities, convert to the same units first. Multiply or divide every part by the same nonzero number to obtain an equivalent ratio. For fractional parts, clear denominators before simplifying.

Example

\(\dfrac34:\dfrac56=9:10\), multiplying both parts by \(12\). Also \(1.2\text{ m}:45\text{ cm}=120:45=8:3\).

To divide \(\$660\) in the ratio \(8:3\), there are \(11\) equal parts. One part is \(\dfrac{660}{11}=\$60\); the shares are \(\$480\) and \(\$180\).

In \(A:B=8:3\), \(A\) is \(\dfrac8{11}\) of the total, not \(\dfrac83\) of the total.

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