Whether it's allowance or a dog-walking business, kids are often looking for ways to earn an extra buck. Tap into that interest with practice that includes calculating tips, sales tax and commission.

A roll of the dice. A flip of a coin. A game of rock, paper, scissors. Kids are calculating probability all the time. The ability to predict outcomes based on the odds is the focus of this series.

Volume is the measurement of space occupied in three dimensions. Practice calculating the volume of 3-D shapes using a variety of techniques and with real-life examples through a series of engaging problems and questions.