Math for Grownups (30 page)

What if she broke up the house and families into shares? The larger families would have larger shares and the smaller families, smaller shares.

Kathy begins by making some assignments. She gives each adult 1 share. All the kids are under 12, so it makes sense to give them a ½ share each.

Another chart arranged by families might help.

So there are a total of 11 shares. Now what?

If the total cost of the beach rental is $3,695, and their groceries last year totaled $1,200, then the entire cost for the week was $4,895. What would happen if Kathy divided that sum by 11? Wouldn’t that give her the price per share?

4895
/
11
=
445

By Kathy’s calculations, each share is worth about $445. Now she needs to find out how much each family owes. Another chart!

Looking over her work, Kathy realizes that she could assign the shares very differently. (For example, there could be value in having a “single room,” rather than sharing a bedroom.) But this looks like a fair start, anyway.

She crosses her fingers that her brother, sisters, and mom agree.

Kathy really had no idea how to solve her problem at the beginning. There was no formula that she could use or process that she learned from high school. Instead, her plan came from a little bit of brainstorming and a lot of common sense.

For her, creating charts helped organize her information. And she wasn’t afraid to try something, such as randomly assigning shares. She also realized that there are probably different ways to solve this problem and that her siblings might not agree with what she came up with.

This is an example of how math can be used to get to an answer, but not necessarily the only answer. It’s also an example of how a process develops from exploration.

Math in school is about following a set of steps. Math in everyday life is about taking some chances, seeing what works and what doesn’t, and not being afraid to try.

Going on vacation means packing, finding someone to take care of Fido, and taking some time off from work. It also means charging some pretty hefty items on your credit card.

The finances of vacationing can boggle the mind. And even with online trip planners and the ability to comparison-shop with the click of a mouse, planning a vacation can make you ready for
another
vacation.

Red and Emily are ready for their second honeymoon. After 25 years of marriage, two kids, and the stress of everyday life, they deserve it. So Red is going to surprise Emily on their anniversary with a 1-week getaway to Aruba.

For 5 years, he’s been secretly putting away a little cash here and there. He’s got $7,500 saved up, and that’s just enough to whisk his bride away for some R & R. (That’s romance and rest.) Red has even arranged for Emily to take some time off from work.

But first he’s got to figure out how he can spend his vacation nest egg. After Emily goes to sleep, he cruises trip-planning websites looking for the best deal. And he’s very quickly overwhelmed.

There are all-inclusive packages, non-inclusive packages, romance packages, and adventure packages. Some include the cost of flights and drinks and meals. Others offer some combination of these features.

It’s going to be a long night.

Within an hour or so, Red has some options scribbled down on a piece of paper. He has chosen their destination—a secluded resort with 5-star dining, access to a private beach, a spa, and great online reviews. Now it’s on to the pricing. There are a number of options:

• All-inclusive, including travel: $7,225

• Romance package (all-inclusive, without travel, and including a champagne breakfast and moonlight cruise): $6,150

• Hotel + Travel package, without activities, meals, and drinks: $4,140

• Everything à la carte: $3,450

Because two of his options don’t include airfare, Red prices out some flights. He finds out that he can get two round-trip tickets for about $925. Not bad!

If he chooses a non-inclusive option, he’ll need to pay for meals, drinks, and activities. And that requires more research. Red wonders whether there is a good way to estimate these.

He considers meals first. The resort includes a free breakfast, so he won’t need to include that in his calculations. But unless they’re going with the all-inclusive option, they will have to buy lunches and dinners. Red does some more research and comes up with the following numbers:

Average lunch
→ $25/person

Average dinner
→ $60/person

And because there are two of them, and they’ll be there for 7 full days:

Lunches: $50 per day for 7 days
=
$350

Dinners: $120 per day for 7 days
=
$840

It looks like the cost of meals will be $350 + $850, or $1,190.

He and Emily aren’t big drinkers, so that’s pretty simple to figure out. Assuming that the cost of drinks is pretty high, he guesses $25 a day for two fancy cocktails, and if they have a nice bottle of wine with dinner each night, that’ll run them about $200 for the week.

($25 • 7)
+
$200
=
$375

Now, Red thinks about activities. A day on a sailboat and some snorkeling sounds great ($450). Then he’d like to book a few spa treatments for Emily ($500).

$450
+
$500
=
$950

Because all of the prices so far have included tax, Red doesn’t need to do any math for that. But he will need to tip the baggage carriers, taxi drivers, servers, and spa staff. Red takes a shot in the dark, and guesses $350 for all gratuities. (That could be too much, but it’s probably not going to be too little.)

This is a ton of information, and Red’s legal pad looks like a football coach’s playbook. He’d better get organized if he wants to book this trip and get some sleep. Red decides to make a list.

Now Red can really consider his options.

The most expensive choice is à la carte, but all of the totals are pretty darned close. If he goes by price alone, the clear winner is the Hotel + Travel package. But that requires him to handle everything on his own—and honestly, he’s ready for bed.

On the other hand, the Romance package is only $70 more. And right now, that extra bit of cash seems worth it. Red pulls out his credit card and books their flights and vacation packages. Then he snuggles up next to Emily and savors his little surprise!

There’s probably no other destination in the world more math-centric than Vegas. Between the gambling and 2-for-1 prime rib dinners, math problems abound.

Winning isn’t everything, but too many Vegas vacationers incorrectly assume that they can come home with more money than they brought. These high hopes translate into high energy.

It’s not until you leave that you notice the big rip-off.

But why is it so hard to win at gambling? The answer is simple: The odds of your winning are very, very low. Of course, the actual odds depend on the game itself. You can lose your shirt in an hour’s time playing slots, but with a little strategy, you
might
come out on top at the craps table.

Still, these games are designed to favor the casino itself. (They are profit-seeking ventures, after all.) And so gamblers are well advised to keep an eye on their bets.

Despite all of these truths, Zoe is absolutely thrilled to go to Las Vegas with her girlfriends. And this story gets even better—she won the trip in a random drawing at her local hard-rock radio station. With this winning streak, she’s sure to hit the jackpot!

She doesn’t want to think too much, and she finds slots incredibly boring, so Zoe decides that roulette is her game. As soon as she unpacks in the casino’s hotel, she heads down to the roulette wheel to get her bearings.

Roulette is a very simple game, it turns out. The object is to predict where the ball will land on the wheel. Each of the 38 slots is numbered (0, 00, and 1ߝ36) and is either red or black (except for the 00 and 0 slots, which are green). Zoe watches the game for a while, looking for patterns and possible strategies.

Pretty quickly, she notices that there are several different ways to place a bet. She wonders if there is a list in her Vegas guidebook, so she pulls it out of her back pocket to check. Sure enough, there is: