An exchange rate is the rate at which one currency is exchanged for another.

Describing exchange rates with ratio

Maths

The multiplicative relationship is extended in the future unit by considering percentages and the connections between multiplicative relationships and direct proportion. By building on a secure understanding of fractions and ratio, pupils can see their understanding of multiplicative relationships being extended.

In the prior unit, pupils generalised and developed their fluency of multiplying with fractions. In this unit, this understanding is extended to ratio and connections between ratios and fractions are explored.

This unit introduces the concept of multiplicative relationsihps, and connects fractions to the idea of ratios. Ratios are then explored in depth and used to solve contextual problems such as those involving exchange rates and general conversions.

Understanding multiplicative relationships: fractions and ratio

Complete the sentence:  The multiplicative relationship between 2 currencies is called the {{ }}.

Select the graphs that show a multiplicative relationship.

Use the graph to convert £55 into dollars ($).

Use the graph to convert $50 into pounds (£).

£1 : $1.92. Use this exchange rate to convert £250 into dollars ($).

£1 : $1.92. Use this exchange rate to convert $672 into dollars (£).

Complete the sentence: When using a ratio table you find the {{ }} relationship.

What number is represented by the question mark in this bar model? 

A bunch of flowers contains red and yellow flowers in the ratio 3 : 5. There are 10 yellow flowers. How many red flowers are in the bunch? 

The ratio of flour to butter to sugar in a cookie recipe is 3 : 2 : 1. You use 180g of butter. How much flour is used?

Andeep, Sam and Sofia share some sweets in the ratio 3 : 8 : 5. Sam gets 24 sweets, how many does Sofia get?

The lengths of the sides of a triangle are split in the ratio 3 : 8 : 7.  The shortest side is 3.6 cm, what is the length of the longest side?

Starter Quiz