By Davide Penazzi
British Rishi Sunak has proposed that pupils should continue learning maths until 18 in order to obtain the numeracy skills needed in careers and everyday adult life.
The proposal might be useful to teenagers but what about those of us who have started grappling with adult life, and might feel anxious every time we encounter numbers?
Many suffer from a real phobia – mathematics anxiety – of numbers, calculations and even the word “maths”.
Buy there are many times in our daily life where knowing some maths can be helpful to make good decisions. Here are just a few examples to get you started using maths more confidently.
1. Use ratios to adapt a recipe
You’ve found a great recipe you want to try, but the recipe serves four and you’re cooking for three and don’t want to use extra ingredients.
Ratios can help you work it out. This means dividing something up into parts. Where the recipe calls for four parts of something, you need only three.
Mathematically, you can say that what you need compared to the recipe is on a 3:4 ratio. Or, you could use the fraction ¾; the mathematics to solve it is the same.
If the recipe calls for 120g of flour, you know that that’s to serve four. To find one part, divide 120 by four. Use a calculator – no problem. One part is 30g of flour. Then multiply by the three people you’re cooking for. This gives you 90g of flour for your recipe.
If the recipe said six teaspoons of oil, how much oil would you need? Divide it by four, which gives you one and a half.
You then need three lots of one-and-a-half teaspoons – that’s four-and-a-half teaspoons of oil for your recipe.
2. Understand averages to see if you need a salary increase
There are various ways of working out an average.
Another way of understanding averages is to use the median.
This essentially means ordering all the people in a line from the one who earns the least to the one who earns most, and picking the one in the middle.
Their earnings would be the median. This is more meaningful, because it means that just a few people earning much more than others don’t skew the average.
According to Stats SA, the median (average) earning for full-time workers in South Africa is R24 813 a month.
If you earn much less than the average salary for your industry, this doesn’t necessarily tell you a huge deal, because it could also include the earnings of CEOs.
But if you earn a lot less than the median, it could be worth figuring out why.
3. Use mental division at a restaurant
Having calculators on our phones can make splitting the bill at a restaurant easy, and there’s no shame in using one.
But there might be times when your phone is lost at the bottom of a bag, or out of battery. Being able to do the maths in your head is a great skill to have.
The best way to do quick division is to develop your own methods to make it easier. This could involve rounding the figure up or down to a number that is easy to split by the number of people at your table.
Imagine you have to split a R2 000 bill between four people: 92 is nearly 100, and we know that 100 divided by four is 25. But 92 is eight less than 100, so we need to take that eight off the bill.
Work out a route for a hike
Perhaps you’re planning a trip with some friends, and it involves a sightseeing walk through a city or a countryside hike.
You want to plan a route that suits everybody and won’t leave you stranded and far from your destination when it gets dark. Maths can help you.
More than a century ago, a Scottish mountaineer devised a formula called Naismith’s rule.
It says that when planning a route, allow one hour for each 5km you will walk, and, if you’re going uphill, add 10 minutes for each 100m you climb.
If your planned route is a 15km hike with 600m of climbing, this would take you three hours plus one extra hour: four hours in total.
Once you’ve worked that out, another mathematical skill can come in useful: estimation.
Perhaps your walk will be more of an amble – so add on a bit of time. You’re going to stop for lunch, so an hour to eat.
You might end up giving yourself about six hours to complete your walk, and now can figure out what might be a good time to set off.
Mathematics is there to help you. With the right mindset, everybody can learn mathematics.
Davide Penazzi is senior lecturer in mathematics, University of Central Lancashire
* The views expressed do not necessarily reflect the views of IOL or Independent Media.