Bud Abbott, the landlord, collects thirteen week's worth of rent at $7 a week from his tenant, Lou Costello. Lou argues that he only owes $28. Perplexed by what Lou is saying, Bud offers to give Lou the room for free if he can prove to him why the answer is $28.

Number 12 sings about the different shapes and arrays that they can become.

Teaches multiplication using the number 3.

Jason Silva explains why competition is an instinct and has positive contributions to humans.

Engineers and scientists in the US are creating more aerodynamic suits for athletes for Team USA in the Winter Olympics to optimize their speed and reduce drag so they can perform their best.