Three Act Tasks

Today in grade 9 we did 2 different 3 act tasks to explore linear relations. The first one we did was Crazy Taxi.

We watched act 1 and we noticed and wondered for a bit. There’s lots going on! We talked about price and speed and distance…then we watched this video to see more and to get prompted with what to calculate. We looked at what the cost would be for a trip that was 30km.

Students used several representations, making tables, and equations and graphs to solve the problem.

After graphing and making equations, they were given an extension question: if you have $30 how far could you travel?

Graphs were extended, tables were extended, equations were solved and we all agreed on an answer. The final video, for Act 3 is here. It shows the answer to the question posed in the 2nd video.

Our 2nd 3 act task was “Fast Clapper”.

here is the act 1 video which we watched, then noticed and wondered. We decided we needed more information to see if he would break the posted record or not.

The act 2 video shows a counter on the screen which helps us do some calculations to solve the problem.

Some groups found out how many seconds it takes for 1 clap, then used that to figure out how many claps he can do in 1 second, and then in 60 seconds.

This group found that he could do 63 claps on 4.6 seconds, which they said was about 4.5 seconds, and that 4.5×13.33 equals 60, so 63×13.33 would be the number of claps. Great use of proportional reasoning. They knew that they were over estimating since they used 4.5 instead of 4.6 seconds.

This group extended a table, counting by 5 second increments to figure out how many claps there’d be in a minute. They were showing that they understood the use of proportions and rate. There would be 5 times as many claps if we have 5 times as many seconds.

Lots of our work hinged on the idea that the rate stayed the same the whole time. We were not sure if he’d slow down or speed up during the minute, but that would also affect our calculations.

here is the act 3 video with the final reveal

We then wanted more information so we looked up to see if he is still the fastest clapper in the world. (Spoiler alert: he is NOT!)

Here’s a video about the current fastest clapper