Library Guides: Math Skills Overview Guide: Understanding Ratios & Proportions (2024)

FAQs

How to understand ratio and proportion? ›

A ratio is an ordered pair of numbers a and b, written a / b where b does not equal 0. A proportion is an equation in which two ratios are set equal to each other. For example, if there is 1 boy and 3 girls you could write the ratio as: 1 : 3 (for every one boy there are 3 girls)

Students in grade 6 understand that a fraction is a way of comparing a part to a whole. They can use this knowledge to develop an understanding of ratios.

What is the "vertical" way to solve a proportion? Use the relationship between the top and bottom number of the fraction. If you can multiply or divide the top number to get the bottom number, this method is the easiest.

The golden ratio, also known as the golden number, golden proportion or the divine proportion, is a ratio between two numbers that equals approximately 1.618. Usually written as the Greek letter phi, it is strongly associated with the Fibonacci sequence, a series of numbers wherein each number is added to the last.

Ratio tells us how much of one thing there is in relation to another thing. For example, 'For every 2 apples we have 3 bananas'. Proportion tells us about how much of one thing there is in relation to the whole amount of something. For example, 'There are 50 pieces of fruit, and 1 in every 5 of those is an apple.

Ratios and proportions are not only used in arithmetic, but are also commonly used in algebra (and geometry). A ratio is a method of comparing two or more numbers or variables. Ratios are written as a:b or in working form, as a fraction.

Students have prior knowledge of natural numbers, integers, fractions, decimals and percentages as well as factors, multiples and primes and will have met simple ratios and rate problems in primary school. They will also have met probability in primary school which involves ratio.

Like fractions, ratios can often be simplified. To simplify a ratio, divide all parts of the ratio by their highest common factor. For example, the highest common factor of both parts of the ratio 4:2 is 2 , so 4:2=2:1 4 : 2 = 2 : 1 .

The 3 ways to solve a proportion are: vertically, horizontally and diagonally (cross-multiplication). The vertical method is used if one of the ratios has a common multiple between the two quantities. The horizontal method is used if there is a common multiple between both numerators or denominators.

Answer: Simply, a proportion is a statement that has two ratios that are equal. In addition, we can write it in two ways; first as two equal fractions a/ b = c/ d; or the other way is using colon that is a: b = c: d.

How do you write an answer for a proportion? ›

To write a proportion, set two equivalent fractions equal to each other, using the information in the problem. For example, if you know the ratio of girls to boys in a class is 2 : 3, and you know there are 24 boys in the class, you can write a proportion in order to find the number of girls in the class.

Mathematically, an equation can be defined as a statement that supports the equality of two expressions, which are connected by the equals sign “=”. For example, 2x – 5 = 13.