# Shipping Solutions: Convert Customary Measurement

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## Objective

SWBAT convert pounds to ounces to problem solve.

#### Big Idea

Find the best deal at the post office, so the package gets delivered on time!

## Warm-up

5 minutes

We use the Skittles page to determine which is the larger amount. The is a great review. I also extended this a bit to review fractional part of 16 specifically.

We reviewed fractions: 1/4 of 16 is ____? 1/2 of 16 is ____? 1/8 of 16 is ____?

We spiral reviewed this, so the students practice dividing the denominator into the whole number. I chose 16 because there are 16 ounces in a pound, and the students will need to know this for the Independent Practice.

## Guided Practice

15 minutes

As we've writing the problem, I have my students circle the units in the problem as they're reading. This may help identify the needed conversion. I ensure that students are revisiting the problem statement after doing calculations to make sure they are answering the question being asked and justifying their answers. I model working through the calculations for Option A. I let my students work out Option B, and determine which Option is the most cost-efficient and explain why. This is another real-world problem that students took a great interest in---saving money.

## Independent Practice

15 minutes

Michelle is mailing a 12.25 pound package to her grandma. The shipping service charged \$0.26 for every ounce mailed. Or. Michelle can use a flat-rate box that costs \$25. Which is the most expensive option?

So, now my students are working out the second option, and explaining which option is the best (most cost-efficient). Here, students are using Mp 3 to construct viable arguments and critique the reasoning of others. My students have to explain and justify the reasoning they use to solve problems.

## Closure

15 minutes

Using cold calling, I have students report out what they/their partner have noted while finishing up their partner work. My students are very economical, and quickly found out how to save money, and identify which option they would choose. You'll see in the video the mention of 16 pounds, which was also in my warm up. It's important that my students take this step-by-step to problem solve. Simply stopping when they get to the cost of Option B is not enough; they need to then subtract, compare, and justify their answer.