# Savvy mum saves ‘guaranteed’ £5,000 in six months with envelope trick

### Martin Lewis advises on saving money as you get older

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A mum has shared a viral method to help you save an astonishing £5,000 in 25 weeks. As reported in the Birmingham Mail, the envelope challenge is based on a formula created by a German mathematician. Carl Friedrich Gauss, who was en vogue in the 18th century, is credited with creating it. Now many social media users are taking up the idea, praising it as a ‘fun’ way to save.

How does it work?

Create 100 envelopes, each labelled £1 to £100.

Set aside 25 weeks.

Across those 25 weeks, draw two envelopes twice a week – four per week – at complete random.

Once drawn, fill the envelope with the amount of cash written on the front.

By the time you reach the 25th week, you should have just over £5k.

In the 18th century, Mr Gauss realised if you split the number one to 50, and then 51 to 100 into two groups, you can add them together to reach 101.

One plus 100 is 101, and two plus 99 is 101, Mr Gauss realised.

Thus, the total of the two groups is therefore 50 times 101.

That works out at 5,050.

On Facebook, the hack has spread like wildfire, with 11,000 likes and well over 30,000 comments from people eager to give it a go.

The viral money hack – which owes a huge debt to maths – has left many impressed.

The original post from the mum urged fellow Facebook users to give it a go.

She wrote: “If you have a three-year plan to buy a house, you could have a little over \$30,000 for a down payment by doing this.”

Sounds good, right?

Of course, there is a slight pitfall – not everybody can afford that amount of expenditure every week.

But others said it was “fun” and said they would give it a go.

One commented: “I love this idea. It would be a fun way for us to save up for something special.”