Puns in Convo

Welcome to Professor Punsley's notes on using wordplay in everyday conversation. Here's the lowdown:

Why was the math book sad? Because it had too many problems.
Why did the cat take a selfie? To get a purr-fect shot.
What do you call a group of cows playing instruments? A moo-sical band.
Why did the scarecrow win an award? Because he was outstanding in his field.