First, you calculate the total amount of parts : 7 + 3 = 10 Next, divide the number by the total amount of parts : £500 ÷ 10 = £50 After that, you multiply the answer by the amount of parts needed on both sides of the ratio : £50 × 3 = £150 and £50 × 7 = £350 Finally put these answers back into the ratio : £150:£350
To check, make sure both sides of the ratio add up to the original number : £150 + £350 = £500
