Think of a product you typically buy from the store that comes in various sizes or quantities. Try to think of a product you use often. For example I could choose a specific brand of water bottle. This water bottle brand sells single water bottles, six packs of water bottles, and cases of 24 water bottles.
Look up the price of the different sizes for this product you have chosen online. Also write down the quantity that you purchase for each size you look up.
Once you have found all of this information find the unitary rate of each of the different sizes. For example, if the six pack of water bottles costs \$8 then my unitary rate for this size would be 8 \div 6 = 1.33 . Adding the correct units gives \$1.33 per bottle.

Post-Investigation Questions

Compare the unitary rate you calculated for each size. Which size is the most cost effective for you to buy? Why?
Do you think the unitary rate for your product would be different in a different state? How about in a different country? Why?
Why are unitary rates so useful in real life? Brainstorm some reasons.
Compare with a friend! What was the most cost effective size for their product? Why do you think that is? Was the same size most cost effective for yours?

Optional

Pick another state or country and find the unitary rates for the same product you chose.

Slightly advanced problems involving applications on percentages, profit & loss, overhead expenses, Discount, tax.