Here’s the download link, which includes the third act.
— Kate Fisher (@_K8Fisher) February 20, 2014
I dunno, this one made me wish the follow-up showed him just throwing the paint away and starting over. Thereâ€™s just not enough investment in materials & time to make me think past. Plus if 6 tablespoons was enough paint to do the job then 30 is just a waste of paint far in excess of throwing away 6.
@Don, what if he had used up all the white paint after putting in the 5 scoops of white? Then heâ€™d have to figure out how to do it by just adding more red.
2014 Mar 11. Great extension for Algebra students from Paul in the comments:
I used the task to set up this question in an Algebra class.
The students were very puzzled when their intuition about the solution did not match arithmetic or a demonstration with cubes.
â€œI have two cans of pink paint variations in the following ratios. Neither is perfect.
Nanaâ€™s Pink 5 Reds : 1 White
50/50 Pink 1 Red : 1 White
I think that a perfect pink will be 3 Reds : 1 White
Can I make it by mixing Nana Pink and 50/50 Pink?â€
Students expected the solution to be one cup of each. How wonderful the sound of a perplexed group of students when their arithmetic did not match their intuition.
Sense making ensued for many minutes with pictures, cups with cubes and more arithmetic.