Maths is everywhere. Day to day life with replete with opportunities to make things easier for ourselves using mathematics, yet many people feel as though it has no real bearing on their existence. One of the most difficult things about getting children interested in maths is that it seems like a set of abstract concepts, and they don’t see the relationship maths has with the world around us. Learning ways to apply things like decimals and fractions in real life can make your life easier, and gives you some concrete examples to cite if a child asks you why he or she should bother learning about them.

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## Adapting recipes

Most recipes you’ll encounter will be designed for a set amount of people, and this is often three to four. If you’re just cooking for yourself or have a small family, the quantities listed in recipe books and on websites will result in you making the wrong amount of food. Applying fractions makes this simpler. If a recipe is designed to serve four, but there are only two of you eating, you should use one half (1/2) the amount of each ingredient, or if there’s only one of you a quarter of each amount will be right (1/4).

To work this out, you just divide by the denominator (the bottom number of the fraction). This is because 1/4 is actually a way of saying one “whole” divided by four. So if you’re cooking for yourself, you divide everything in the recipe by four. If there are more than just you, work out the fraction for one person and multiply the answer by the number of people.

## Visualising percentages

Percentages provide a more precise value for a proportion, but they can be difficult to visualise and understand in some cases. Imagine you read a study which finds that 8 percent of people in the UK are unemployed. This number is quite low, so you might be tempted to think that it isn’t much of an issue, but if you think about the number as a fraction the issue becomes more clear. Percentages are just fractions of 100, so you can work out a more understandable figure by dividing each part of the fraction by the same number. You could say that 4/50 people are unemployed, or 2/25 or around 1/12 – by dividing the numbers over and over again you arrive at the most accurate figure you can visualise. That would mean one out of every twelve people doesn't have a job.

## Checking your change

The most common use of decimals is through money. This means decimals are useful in many cases, such as working out how much change you should receive when you buy something. Imagine you're purchasing something for £8.79 and paying with a ten pound note. The leading eight might lead you to expect two pounds in return, but you can use the decimals to get a more accurate result. Subtract the decimal number from 1 to work out how much small change you'll receive, remembering that 1 = 1.00. This means you need 21 pence (an answer of 0.21), and you've now accounted for the decimals in your calculation. Adding this 21p onto the overall price quickly reveals that you'd still need an extra pound, so £1.21 change in total.

## Calculating percentages

Since a percentage is a fraction of a hundred, 79 percent can also be expressed as 0.79 – or as a fraction 79/100. This close relationship means that if you need to work out a percentage of a bill you should tip, you can simply multiply the total bill by the relevant decimal number to see how much you should give. If your bill is £64.93 and you want to tip 15 percent, multiply the number by 0.15 to find out that you should tip around £9.70 to give the waiter 15 percent. This requires a calculator, but it’s the easiest way to find a percentage of anything!