Maths that lives on your street
A lower unit rate can still cost you more. Treat gas and electricity as a two-part tariff, write each deal as a straight line, and find the usage point where the cheaper-looking option stops being cheap.
A '50% off, then an extra 50% off' window can look like a free coat. It isn't. Here's the multiplier algebra that turns layered Black Friday stickers into one honest final price — and helps you compare them with a straight reduction.
Your buy-nine-get-one-free card feels like a gift from the café. Run the numbers and it's a 10% rebate—one you fund yourself, stamp by stamp. Here's how it stacks up against cashback apps and straight discounts on the high street.
A late-night station vending machine that takes exact change turns your pocket into a small algebra problem. With a £2 coin, a £1 coin and a handful of smaller change, some prices are easy, some are impossible, and one is exactly a penny out of reach. Here is how to spot the difference before you join the queue.
Your satnav promises a tidy arrival time, but the trip is a sequence of moving and waiting. Here is how to turn a high street, an arterial road and two pelican crossings into a piecewise function - and why the average speed you calculate is more honest than the one on the screen.
A 20mph school street and a 30mph main road are separated by ten miles per hour on the sign — and by a squared term in the algebra. Here’s how thinking distance and braking distance combine, and what the curve says about parked cars, sightlines and school gates.
School catchment areas look like fixed borders, but the last placed distance is a ranking that moves with siblings and intake. Here's the inequality behind the offer—and why a 200-metre move can still miss.
The post office queue in December is not a mystery — it is a rate with a tail. Here is how to time a branch, count arrivals, and use L = λW to decide whether to stay, return later, or walk to the next high street.
A planning notice can promise 20% affordable housing and still leave you counting on your fingers. Here is how to turn the unit mix, room counts and commuted sums into inequalities you can check before the cranes arrive.
The 20-minute neighbourhood sounds like a planning promise, but around your door it is an inequality with parameters. Here is how to turn walking speed and time into a radius, test your local amenities, and see where the slogan and your street part company.
Your council tax bill is not a mystery; it is a ratio anchored to Band D. This walkthrough shows how the multipliers work, how to scale a Band D figure to your own band, and how to check the leaflet in five minutes.
Behind every street-food burrito is a pitch fee, a van, a gas bottle and a pile of rice. This is the linear algebra of a market trader's Saturday, from the break-even point to the rainy-day decision that changes the whole graph.
The meal deal looks like a simple sticker price, but it is really a small system of equations. Here is how to compare unit prices, test swaps and spot the lunchtime combinations where the deal quietly costs you more.
Rent is a single number, which is why it wins every argument. Travel is a rate, which is why it quietly loses. Put both flats into a pair of simultaneous equations and the break-even point does the arguing for you — usually at around two and a half office days a week.
Your council hasn't given you a list of dates. It's given you a repeating sequence, and the whole thing collapses into a single remainder calculation. Here's how modular arithmetic predicts bin day, bank holiday shifts and the handful of weeks each year when every container on your street goes out at once.
A second urn looks like a £250 fix for a queue problem. At a UK Christmas market, it is really a break-even question: how many extra cups does the upgrade need to sell before the foam settles? Here is the algebra, using realistic pitch fees and cocoa costs.
An allotment is not a vibe; it is a set of constraints with a harvest at the end. Here is how to turn bed space, watering time and sunlight into a feasible region, then test the corners before you order next season's seeds.
A railcard is a bet on your future journeys, and the break-even point is an inequality. Here is how to use your typical fare and trip count to decide whether the card actually saves you money.
The sign says 'from £2.20 per hour', but the meter charges in blocks, fixed fees and marginal jumps. Model a UK car park as a piecewise function and the true cost of your stay becomes much clearer.
A council with a repair backlog cannot fix every pothole, so it often uses a weighted score to decide what gets fixed first. Here is how variables, coefficients, budget constraints and linear programming shape the roadworks—and how to score your own street.