The easy way to work out the best value supermarket deals

It all comes down to percentages, with there being plenty of deals to be found at 25% off, buy-one-get-one-half-price and much more.

If you can work out specific deals quickly when browsing , you can determine how much value is gained by taking it on.

Lyndsey Hartley, head of maths at Kelvinside Academy , believes learning to calculate percentages quickly in your head is “one of the most useful things you’ll ever use in life.”

How to make sure you’re getting a good value deal at the supermarket

To best work out the value of supermarket deals, Lyndsey recommends finding what 10% of the price is.

This is because it can be broken down or it can be built up to whatever you need it to be.

She explained: “So, with something that costs £10, or another number ending with 0, you’d just remove the 0.

• 10% of £10 would be £1.
• 10% of £50 would be £5.
• 10% of £100 would be £10.

“If it isn’t a nice number ending in 0, you’re just going to move that decimal point by one place.

• 10% of £15 would be £1.50.
• 10% of £55 would be £5.50.
• 10% of £105 would be £10.50.

“Once you’ve worked out 10%, you’re off to the races.  

“If something’s 5%, just halve the 10%. If something’s 20%, just double the 10%.”

This can be applied to quickly work out the value of supermarket deals, such as with something being 25% off.

Lyndsey continued: “Take 25% off an £8 item.

“Start with 10% – that’s 80p.

“Double it to get 20% (£1.60), then add half of that again to reach £2.

“So the final price should be £6.”

Additionally, buy-one-get-one-half-price deals can also be broken down quickly.

She shared: “If one item is £6, the second at half price makes two £9 in total.

“That works out at £4.50 each – so it’s only a real saving if you actually need both.”

Finally, deals like ‘25% extra free’ can be sense-checked in seconds.

Lyndsey explained: “If there are 8 rolls, 25% is a quarter – which is two more – so you’re getting 10 in total.”

One tip to keep in mind when working out supermarket deals

As a further tip to help work out the value of supermarket deals, Lyndsey suggests using the £1 rule.

She shared: “If you tell yourself that you only need to be accurate within £1, that instantly lowers the pressure massively.

“Remember, you’re not sitting an exam here, you’re just sense-checking, and that small permission can really help make people feel far more willing to try.”