Mr. Lutke can grade 10 papers in 35 minutes. How many papers can he grade in 2 hours?

Can you write a proportion for this and solve it?

I can solve word problems using what I know about proportions.

Let's review cross-multiplication:

Multiply one part of the cross, write an equal sign, multiply the other part of the cross.

Solving word problems involving proportions is just like solving regular proportion problems (you use cross multiplication, then divide both sides by the number in front of the variable). The only difference is that you have to write the proportion from the problem instead of it being given to you.

Let's do some examples:

1. A car travels 210 miles in 3 hours (at a constant speed). How long will it take for it to travel 280 miles?

2. 40 Paydays cost $50. How many Paydays can you buy if you have $75?

3. A picture frame is 9 inches tall by 6 inches wide. If the height is reduced to 3 inches, how wide is the smaller frame?

Keep in mind:

• Make sure you organize your information correctly in your proportion (the top of both fraction should be the same units, and the first fraction should be for one part of the scenario, and the second is for the other)

• Remember that you won't always get a whole number answer. If you don't, keep it as a fraction and reduce if possible.

Today, let's start our work with a neighbor and work alone when we're ready!

Try these problems for a 3

Do these for extra credit! One point per side (but you must show your work using proportions)