Lego by the House-ful

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

Lego by the House-ful

May 22, 2018

Lego is one of those toys that every kid has heard of, and that almost every kid has played with. Ever since it was invented in 1958, Lego pieces have had the exact same thickness of brick, and the same size studs (the little bumps on top). They’ve made 4 billion minifigures since then, which equals half the world’s population! Now they design 130 new sets each year, like the Star Wars sets, plus they keeping selling the longtime sets. So our longtime fan Benjamin H. asked, how many Lego pieces are made every day? Lego’s website says that in one year they make 45.7 billion Legos. If we divide by 365, that comes to 125 million pieces a day, and a bout 5 million every hour. Given that a 1-foot cube can hold only about 400 pieces, you can imagine how many houses you can fill every day with Lego!

Wee ones: If you snap together a red Lego brick, a blue brick, a green, a yellow, a white and a black, how many bricks have you snapped together?

Little kids: If a Lego brick has 2 rows with 4 knobs (bumps) each, how many knobs does it have?  Bonus: If you snap a 2-knob piece on top, how many knobs from the bottom piece are still showing?

Big kids: To find how many 1-foot cubes a room can hold, you just multiply the length times the width times the height to the ceiling. If your bedroom is 10 feet by 10 feet with an 8-foot ceiling, how many cubic feet of Lego can you fill it with?  Bonus: If each cubic foot can hold 400 pieces, can the room hold 1 million Legos? Can it hold the amount made in about an hour? (Hint if needed: What if each cubic foot held only 4 pieces…then try 40 pieces…)

The sky’s the limit: How many different rectangle shapes (number of knobs across and front to back) can a piece with 36 knobs on top have? (Assume that you have at least 2 knobs in either direction, but you don’t have to worry about which way each combo is facing.)













Wee ones: 6 bricks.

Little kids: 8 knobs.  Bonus: 6 knobs — or 7 if the 2-knob piece is hanging off the edge.

Big kids: 800 cubic feet.  Bonus: That room holds 320,000 pieces…so no, it doesn’t hold 1 million…and you’d need more than 15 bedrooms to hold the more than 5 million Legos made in 1 hour!

The sky’s the limit: There are 4 ways: 2 knobs x 18 knobs, 3 x 12, 4 x 9, and 6 x 6.

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About the Author

Laura Overdeck

Laura Overdeck

Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.

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