It’s fun to make things out of Lego, like cars and robots. Well, imagine if you made a Lego factory that could make Lego cars! This factory isn’t the speediest, but it really runs on its own. So if it’s bedtime and you need 100 cars made by tomorrow, it can do the job overnight.

*Wee ones:* If the Lego car starts with 4 wheels and a floor, how many pieces does the car have?

*Little kids:* If every car needs 2 pairs of wheels, how many pairs do 3 cars use in total? *Bonus:* If you have 10 pairs in stock, how many cars can you make?

*Big kids:* If right now the robot makes 1 car every 30 minutes, how fast would it make a car if it made them twice as fast? *Bonus:* At the new speed, how many can it crank out in 1 hour? (*Reminder if needed:* An hour has 60 minutes.)

*The sky’s the limit:* Without multiplying it all out, can you tell who will finish first: a robot building 28 cars spending 6 minutes on each, or a robot building 50 cars spending 3 minutes on each?

Answers:

*Wee ones:* 5 pieces.

*Little kids:* 6 pairs of wheels. *Bonus:* 5 cars.

*Big kids:* 1 every 15 minutes. *Bonus:* 4 cars per hour.

*The sky’s the limit:* The 2nd robot will finish first. It’s making fewer than double the cars, but at exactly twice the speed. If you *did* multiply it all out, you’d get 28 x 6 = 168 minutes for the 1st robot, and 50 x 3 = 150 minutes for the 2nd.