Ratios – 5.01a

Ratio, Proportion, and Rates of Change II – OCR GCSE (J560)

In this course, Dr Thomas Woolley (Cardiff University) explores ratios, multiplicative relationships, and proportionality, covering Topics 5.01a, 5.01b, 5.01c, 5.01d, 5.02a in the OCR GCSE (9-1) in Mathematics (J560) Specification for Foundation Tier and Higher Tier. In the first mini-lecture, we introduce ratios and ratio notation before learning how to simplify ratios using the highest common factor (Topic 5.01a). In the second mini-lecture, we learn how to relate ratios and fractions (Topic 5.01b, 5.01c, 5.01d). In the third mini-lecture, we introduce unit ratios (Topic 5.01a, 5.01d). In the fourth mini-lecture, we discuss multiplicative relationships (Topic 5.01b, 5.01c). In the fifth mini-lecture, we learn the relationship between proportionality and ratios (Topic 5.02a). In the sixth mini-lecture, we extend our understanding of ratios to linear graphs (Topic 5.01d).

Ratios – 5.01a

In this mini-lecture, we cover Topic 5.01a by introducing ratios. As we move through this mini-lecture, we consider: (i) common ratios such as 1 : 1 and 1 : 2 in ratio notation; (ii) ratios in everyday scenarios: diluting squash with water, determining the cost per item in a store; (iii) how to simplify ratios by multiplying or dividing both sides by the same factor; and (iv) how to simplify ratios using the highest common factor (HCF).