Natalie Haynes: Turn the 100 metres into the 50 metres

Even though I don't balance budgets for a living, I do know that if you double them, that makes them bigger. So this immediately makes me better qualified to balance the Olympic budget than Hugh Robertson, the sports minister. He fondly believes that the £500m contingency fund will easily cover the fact that the security costs alone have almost doubled from £282m to £553m.

And that's before the Prime Minister stepped in to double the budget for the opening and closing ceremonies (that's four ceremonies in total – Olympics and Paralympics). Oddly, this isn't being seen as a massive waste of cash which might more profitably be used on virtually anything. Hugh Robertson said it was to "drive the maximum benefit for the economy and for tourism. It's about the impression that people take away of this country."

He seems impervious to the fact that the main impression they are likely to take away is that we can't tank as much money on fireworks as the Chinese did four years ago.

With more than half the contingency fund gobbled up on these two things alone, I suggest we may need to cut corners from other parts of the Games if they're still to come in on budget. We need to scale down our ambitions a bit. First, we should reduce the Olympic rings from five to three. And let's give the torch-relay a miss, too – fuel isn't cheap, you know. We could just cadge a light off some bloke in the crowd at the opening ceremony: that should be fine.

We'll need to apply a bit of austerity to the events themselves, obviously. Usain Bolt can run in the men's 50 metres, and that will be just as good. Chances are, he'll go even faster than he does in the 100m, so that's bound to create some of those good impressions the government is keen on.

We should also make sure we don't waste money on expensive racing bikes when the Boris bikes can be hired for a few quid a time. Given that they weigh roughly the same amount as a small car, the athleticism required to get them uphill in a road race will be all the more impressive.

Finally, the long jump requires a large sandpit for the competitors to land in. This could be provided in a time-share with the nursery schools of Newham, which could also do with a nice big sandpit. Extra points will be awarded if a jump results in the discovery of a missing piece of Lego. If enough Lego is found, we could use that to build the podium for the athletes to receive their medals. And, as for those, I'll have some chocolate coins going cheap in January.