LIVETUTORIALS LEARNING LIBRARY
Ratios and Proportional Sharing
Translate a ratio into equal-sized parts, divide a total proportionally, and check that the shares reconstruct the total.
Overview
A ratio compares quantities in a stated order. A:B = 3:5 means that for every three equal units assigned to A, five equal units are assigned to B. The numbers describe relative shares rather than the actual quantities until a total or another relationship is supplied.
When a total is divided in a ratio, add the ratio parts first. The total divided by that sum gives the value of one part. Multiplying by each ratio number gives the corresponding share. Keep the order of the labels fixed throughout the calculation.
Ratios also help with scaling recipes, comparing groups and interpreting mixtures, but part-to-part ratios and part-to-whole fractions are different statements. In a 3:5 mixture, the first ingredient is three eighths of the total, not three fifths. Use the linked tutorial to practise that distinction.
Continue learning
- Divide a Quantity in a Ratio
Convert ratio parts into actual shares, distinguish part-to-part and part-to-whole comparisons, and verify a proportional split.