8.2.1 Salad Dressing Recipe
Activity: Salad Dressing Recipe
You have a recipe for salad dressing that serves 8 but want to know what proportion the oil and vinegar are in so that you can make it for any number of servings.
The recipe is:
- 50 ml olive oil
- 15 ml white wine vinegar
Work out the ratio of oil to vinegar.
To find the ratio of two values, you should use division.
For the oil to vinegar ratio, you should set up the calculation .
So there is 3.333 times the volume of oil in the recipe compared to vinegar.
You will have noticed that this produces an answer where the 3 to the right of the decimal place is repeated. In fact this continues to infinity and is known as a recurring number. In this case 0.3 recurring is the same as 1 third. Try dividing 1 by 3 on your calculator to check this out.
In this example, you calculated the ratio of one quantity to a second quantity by dividing the first number by the second. You can use this process to calculate other ratios, too.