Most of us are told in school that we would have to use math everyday—which was a somewhat flimsy truth even before every single person in the country carried around a computer in their pocket. But that doesn’t mean all those hours in math class were completely worthless for those of us who aren’t NASA scientists or mathematicians. Here are some surprising ways that math can actually help you in your daily home life.

Use math to get the best deal on pizza.

Pizza advertising can sometimes be a dizzying blitz of deals that promise X pizzas of Y inches for Z dollars. But how do you know if you’re actually maximizing your pizza to price ratio? The answer can be found with a simple sixth-grade math formula.

image
iStock

A video from ASAP Science asks if it is better to get an 8” pizza or a 16” pizza for double the price of the 8” one. A quick consideration would lead you to believe it’s a roughly equal value.

But then you recall that in sixth grade, you learned that the area of a circle is A = π r². This means that the area of the 8” pizza is roughly 50 square inches, while the area of the 18” pizza is more than 200 square inches.

image
iStock

This is because the radius is squared—as the radius increases, the pizza area increases exponentially. So just remember to consider pi when you order your next pie.

Finally, fold a fitted sheet the right way.

Folding a fitted sheet is a riddle as old as time. But would you ever guess that all it would take to solve this linen closet conundrum was the little-known mathematical field known as topology? (Topology is the study of those properties of geometric forms that remain invariant under certain transformations, such as bending or stretching).

image
iStock

As “Math Guy” James Tanton delightfully explains in this video, the key to nicely folding a fitted sheet is to first fold the long elastic corners into themselves, tweaking them until the corners are pinched to nearly form a right angle. This will create a “U” shape of elasticity within the four-cornered square of the sheet.

From there, it is a simple folding into halves, then thirds, then thirds again, to end up with a neatly folded fitted sheet.

Create 120 outfits from just 14 pieces of clothing.

Math has many associations, but it would be a stretch to say it’s often associated with high fashion. However, by using some very basic math and grasping the concept of interchangeability in a wardrobe, anyone with a masculine style can turn just 14 pieces of clothing into 120 different wardrobes according to Real Men Real Style.

image
iStock

The key lies in selecting articles of clothing that can pair interchangeably with one another. This can unfortunately require leaving that bright fuchsia shirt from Vegas on the sidelines. By ensuring that nearly every shirt, jacket, and pair of pants can “work” with the other articles of clothing, simple math lets you calculate how many outfits you can achieve.

For example, if you have two pairs of shoes, three pairs of pants, five shirts, and two jackets, you can get 60 different outfits. (The math is simple: 2 x 3 x 5 x 2 = 60.)

image
iStock

The more accessories—like ties and sweaters—that you can add, the more you multiply the number of outfits that are possible. So now when you’re looking svelte at the club and someone asks who your stylist is, smoothly reply “Math…”.

Become a force to be reckoned with in Monopoly.

Everyone enjoys the friendly competition of a game of Monopoly—it’s all just a roll of the dice and hoping you’ll get the right chance card. But with math, you can turn this family room board game into the cold, calculating battle of probability it really is.

image
iStock

Two major probability factors loom over all other aspects of a Monopoly game: the likelihood of rolling a six, seven, or eight, and the high probability that multiple players will be sent to jail at some point in the game.

All this means is that the chances of someone landing on New York Avenue or Tennessee Avenue are noticeably higher than many other spots on the board, so you can start crafting your strategy to bankrupt your friends in a matter of turns.

Crack the code of unit pricing at the grocery store.

There is a default mindset that many have while grocery shopping that getting the largest quantity container of whatever product you’re buying nets you the best savings. The notion of “buying in bulk” or grabbing the family-sized value pack is well engrained, but is far from guaranteeing you some savings. The only way to do that is to focus on the product’s unit pricing.

image
iStock

Unit pricing is the breakdown of how much you’re paying for something per unit of volume. The budget-conscious among us have been eying these little figures for some time, but even the sharpest mind can get thrown off by trying to calculate which grocery store deals actually net you the most product per penny.

image
iStock

Take into account these hypothetical product volumes and prices from ConsumerCredit.com:

12 oz bottle at $2.89

24 oz bottle at $5.27

48 oz bottle at $9.99

2 pack of 10 oz bottles at $4.

3 pack of 14 oz bottles at $11.39 with a coupon in hand for $1.00 off the package.

From a quick glance one might assume that the three pack with the coupon is the best deal (why wouldn’t it be?). But, using the simple equation of dividing the price by the total volume, it is revealed that the coupon deal comes out to 25 cents an ounce, while the two pack of 10oz bottles is only 20 cents an ounce.

image
The Krazy Coupon Lady

It’s a small difference, but it’s the kind that can add up quickly to big savings (or spending) over a few months of grocery shopping.

Figure out fair rent between roommates.

Roommates are already faced with so many disputes over fridge space, shower times, and who gets to watch what show on television—must the division of rent also cause friction? Not necessarily.

image
iStock

Agreeing to assign certain rents can be determined by using a mathematical formula so that all roommates are reasonably satisfied.

The mathematic method begins with the hypothesis that people have different preferences when it comes to what they will pay for in a room. Some people need space, while others like natural light, and others may just want the cheapest option they can get. Using a method known as Sperner’s Lemma, different parties assign their own values to each of the rooms.

image
iStock

From there, every possible rent division scenario is placed on a large triangle (hypothetically); each corner of the triangle has a specific roommate paying all the rent, while the middle of the triangle represents an even division. The roommates push and pull on potential rents until an equilibrium is reached. The New York Times offers a clear visualization of this method.

So next time it seem like a fight may be brewing over how rents should be assigned, calmly break out some triangles and all your problems will be solved!

Level off a wobbly chair or table on an uneven surface.

If you’ve ever had to place a four-legged chair on an uneven floor you have no doubt struggled to get that chair to stand firmly with all four legs making solid contact to the ground. There is invariably a wobble that will accompany that four-legged piece of furniture in uncertain terrain. Until, of course, math comes along.

image
Ecooe

James Tanton, the fitted-sheet folding genius and self-proclaimed Math Guy, has a math-based solution for this problem as well. As Tanton explains, if you can get two of the chair legs to find stable ground, and if you can rotate the chair so that the wobbly chair legs find a stable location, then there must be an intermediate point where all four legs will be able to touch the ground.

Essentially, between the positive and negative levels there must be a zero level. Find the zero, and you will have found a solid spot of earth for your four-legged chair to sit.