Ratio and Proportion
A ratio compares two quantities, while a proportion shows that two ratios are equal, essential concepts for comparing and scaling quantities
Core concept
A ratio compares two quantities, written as a:b, showing the relative size of one quantity compared to another.
How it works
A proportion states that two ratios are equal, like a:b = c:d, useful for solving problems involving scaling.
Why it matters
To solve a proportion, we can use cross multiplication: if a:b = c:d, then a×d = b×c.
Key detail
Ratios and proportions are used in real life for recipes, map scales, and comparing quantities like speed or price.
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• Ratio: compares two quantities, a:b.
• Shows relative size of quantities.
• Proportion: two ratios are equal, a:b=c:d.
• Useful for scaling problems.
• Solve via cross multiplication.
• a:b=c:d means a×d=b×c.
• Used in recipes, map scales.
• Also comparing speed, price.