# Decimals in Use

## Paychecks and Expenses

### Sample Problem

Luis works 2.5 hours a day, 4 days a week. How many hours a week does Luis work?

2.5 hours/day × 4 days/week = 10 hours/week

Only 10 hours a week? Guess who will not be jumping into a roomful of money? Luis.

## Prices and Counting Change

### Sample Problem

Nathan buys a sandwich for \$6.50. It's one of those "gourmet" sandwiches, which just means that it's a regular turkey sandwich but comes with a packet of dijon mustard. Anyway, he pays with a \$10 bill. Assuming the cashier doesn't screw things up, how much change does Nathan get?

\$10 – \$6.50 = \$3.50

So Nathan gets \$3.50 in change.

## Tipping

### Sample Problem

Kate and Jim ate at a restaurant. The total bill was \$56.80. They want to leave only a 10% tip because their server spilled two drinks and one plate of nachos into their laps. How much of a tip should they leave?

By the way, there's a really quick way to figure out 10% of a bill: just move the decimal point one spot to the left. Kate and Jim's bill was \$56.80, so they can slide that decimal point over between the 5 and 6 to get \$5.68. That's only if they're leaving a measly 10% tip though, which we really don't recommend doing. Restaurant servers have bills to pay too, y'know?

## Sharing Work

### Sample Problem

A librarian has 50 books that need to go back on the shelves. She has her five student helpers divide up the books evenly. How many books will each student put back on the shelves?

books each

Hopefully they're not all enormous bricks like War and Peace.