Ratios – R4

Ratio, Proportion, and Rates of Change II – Edexcel GCSE (1MA1)

In this course, Dr Thomas Woolley (Cardiff University) explores ratios, multiplicative relationships, and proportionality, covering Topics R4-R8 in the Pearson Edexcel GCSE (9-1) in Mathematics (1MA1) 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 R4). In the second mini-lecture, we learn how to relate ratios and fractions (Topic R5). In the third mini-lecture, we introduce unit ratios (Topic R4, R5). In the fourth mini-lecture, we discuss multiplicative relationships (Topic R6). In the fifth mini-lecture, we learn the relationship between proportionality and ratios (Topic R7). In the sixth mini-lecture, we extend our understanding of ratios to linear graphs (Topic R8).

Ratios – R4

In this mini-lecture, we cover Topic R4 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).