# Doing the two-step

Deep Throat: You'll have to figure that on your own.

Bob Woodward: Look, I'm tired of your chicken sh** games! I don't want hints! I need to know what you know!

Deep Throat: [reluctantly] ... the money... everything. ... It leads everywhere. Get out your notebook. There's more. I think your lives are in danger.

So far we've only done one conversion -- we changed miles to feet. On this page, we're going to tackle the whole problem -- changing miles/hr to feet/minute. Ready? Strap on your seatbelt, cuz 4.5 mph is suddenly gonna sound a whole lot faster...

Our basic strategy is going to be, take the whole fraction (4.5 miles/hr), and run it through one conversion for each unit that needs to change.

## conversion #1

In this case, we have 2 units that need to change -- miles and hours. So we'll have to go through 2 conversions.

## conversion #2

Above is a sort of intermediate result -- the miles have been converted, but the hours haven't, yet. So let's fix that. First, make a fraction-that-equals-1 using minutes and hours...

So which one is it? Let's give them each a test drive:

The moral of the story is the same as it was before -- follow the units! The first fraction didn't work out because we couldn't cancel the units. The second fraction works because we CAN cancel. And so we have our answer.

## The faster 2-step

You don't need to do two separate equations for this. Instead, you can simply chain both conversions onto the starting value, like this: