3 Act Math

Act 1

1. How many cups will there be?
2. Write down a guess.

Act 2

3. What information would be useful to figure this out?
4. Write down some questions you have in your head right now.
First Three Cups
Final Cup

Act 3


What would happen if the first cup had a 10.1 cm diameter?
What would happen if the final cup had a 1.6 cm diameter?

Common Core Standards
Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.
add and subtract whole numbers and decimals to the hundredths place using the standard algorithm


13 thoughts on “Cups

  1. Not sure I understand “Sequel” . Is it based of the same pattern of a .5 cm decrease each time? Are they two different problems/questions?


    1. Thanks for the questions! It is based on the same pattern, and they are two different problems. So, the first one will start with a cup of 10 cm and finish with a final cup of 2.6 cm. For the second sequel question, the first cup will start at 8.1 cm and end at 2 cm.

  2. I wonder though. If it decreases by .5 cm each time and you start with 10 cm, it doesn’t work out evenly to end at 2.6 cm? Am I missing something? Thanks!

    1. Thank you Miss Yamamoto. I should have known to look at the thread first. You and I think alike!

  3. My only suggestion would be to change the picture with the measurement and 3 cups. As it is now, the third cup is on the left, then the second, then the first cup. That’s a little confusing when we scan left to right. I might also add a label that says first, second, third cup.

    Great task!

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