5th Grade Singapore Math Experts Take Action

One day while working in their Singapore Math Intensive Practice Book, three 5th grade students noticed something amiss. Although Jeremy D., Anya G., and Rayan R. very carefully calculated their answer to a “Take the Challenge!” question, it did not match the answer given in the book.

After checking and re-checking, they concluded that there was in fact an error in the textbook! Instead of just letting it go, the three students decided to take action and tell the textbook authors what they had discovered, to help them improve the textbook for future students. Here is the email Jeremy, Anya, and Rayan sent to Singapore Math Inc. and the company’s response to the students.

The students' email:

To Whom It May Concern:

We are 5th graders from the International School of the Peninsula (ISTP) in Palo Alto, California. We are contacting you because we have found a mistake in the Singapore Math 5B Intensive Practice book on page 146 “Take the Challenge!” Your answer indicated that the figures A, B, D fit together to make a perfect cube, but that does not work.

However, we found that A, C, D worked! Please find below a summary of our thinking and image to go along with it.

Our thinking:

A cube that measures 3 units x 3 units x 3 units = 27 units3. The volume of A is 7 units3, the volume of B is 9 units3, the volume of C is 10 units3, the volume of D is 10 units3, and the volume of E is 8 units.

A = 7 units3

C = 10 units3

D = 10 units3

10 +10 +7 = 27, and the cubes fit together to form a perfect cube.

Thank you for your time, and we hope to hear back from you.


Jeremy D., Anya G., Rayan R.

ISTP 5th Grade Students

The company's response:

Dear Jeremy, Anya and Ryan,

Thank you for bringing to our attention the error in the Singapore Math Intensive Practice book. While each of our books undergoes a rigorous editorial review before they are released, it is sometimes the case that mistakes do slip through undetected. As much as we don’t like getting caught with egg on our face, it does bring us great satisfaction knowing that there are students such as yourselves that can not only identify errors, but so clearly and visually articulate them back to us. Well done!

All of us here at Singapore Math wish you and your classmates the best.

Kind Regards,

Daniel Brillon

Singapore Math Inc.

We are very proud of Jeremy D., Anya G., and Rayan R. for taking the initiative to reach out to Singapore Math. Even though it might be 'just a math book,' the habit of taking action when something is not right is one important type of Action that the IB encourages. Jeremy, Anya, and Rayan also demonstrated great skills as Communicators to clearly use evidence to support their argument – a life skill that transcends any content area.


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