Chapter 4: The Proof It is Mathematical - ~Math's Secret~

''Wada Don here. Math's knowledge is very strong-ta don! How did she do that? Let me tell you why -- Math studies very hard and becomes a professional mathematical taiko-ta don. So amazing, Math!''

Summary
''Math is quiet because she has a mathematical proof about it when she explains the taikos. Her strong knowledge saves the taikos when she is a professional taiko, when she is studying mathematics a lot.''