L19 Comparison Shopping

L19 Comparison Shopping

I can find different unit rates when given a table, equation and/or graph

Open Ended

Imagine we took a trip to the grocery store and we see that 9 rolls of toilet paper costs $5 and 12 rolls of toilet paper costs $8. How can we determine which quantity will be the better buy?

We can compare different rates by finding their UNIT RATES first ...

• 9 rolls/$5 means that it has a unit rate of $1.80/roll

• 12 rolls/$8 means that it has a unit rate of $1.50/roll

• Therefore, we would save more money in long run if we buy the 12 rolls at $8.

Brain Break

One Must Go: Come off mute and explain which one must go and why

Bryan vs. ShaNiece

Bryan and ShaNiece are both training for a bike race and want to compare who rides his or her bike at a faster rate.

Both bikers use apps on their phones to record the time and distance of their bike rides.

Bryan’s app keeps track of his route on a table, and ShaNiece’s app presents the information on a graph.

Multiple Choice

A rate from Bryan's table is 75 miles/3 hours. What is his unit rate?

• 25 hours/mile

• 75 miles/hour

• 25 miles/hour

Multiple Choice

From the graph we can see that ShaNiece is biking at a rate of 30 miles/2 hours. Her unit rate is...

• 5 miles/hour

• 15 miles/hour

• 2 hours/mile

Poll

So if Bryan's unit rate is 25 miles/hour and ShaNiece's unit rate is 15 miles/hour. Who is biking the fastest?

• Bryan

• ShaNiece

Bryan is biking faster, because he covers more ground in the same 1 hour.

Notice how by comparing the unit rate we are able to decide who is going faster.

Brain Break

Riddle: What has to be broken before you can use it?

Claire vs. Kate

Claire and Kate are entering a cup stacking contest.

Both girls have the same strategy: stack the cups at a constant rate so that they do not slow down at the end of the race.

While practicing, they keep track of their progress, which is shown.

Open Ended

Based on Claire's graph what is her unit rate?

Open Ended

Based on Kate's equation, when time (t) is equal to 1, what is c equal to?

What is her unit rate?

Multiple Choice

Claire is stacking cups at a unit rate of 5 cups/sec. Kate is stacking at a unit rate of 4 cups/sec. Who is stacking at a faster rate?

• Claire

• Kate

Multiple Choice

Kate notices that she is not stacking her cups fast enough. What would Kate’s equation look like if she wanted to stack cups faster than Claire?

• c = 3t

• c = 4t

• c = 5t

• c = 6t

Exit Ticket: Go to the NearPod Code for your homeroom-

(1) join.nearpod.com

(2) enter code

• JSU- 4A3HR

• Spelman- 829SY

• ASU- AXNJD