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Your House, Made of Lego

by Laura Overdeck

What if you could build your own house out of Lego? How many pieces would you need? Luckily for us, a company made an online calculator to help figure that out. You type in your house size in square-foot area, and the number of floors. The calculator uses math to say how many 8-peg Lego bricks are needed to build that house! How does it do it? We know that a Lego brick is about 1/4 inch thick, 5/8 inch wide, and 1 1/4 in long. Meanwhile, a real clay brick is 2 1/4 x 4 x 8 inches. So you need 359 Lego bricks for each real one. Turns out you need more than 10 million Legos to build your average 2,000-square-foot house. But watch out: that covers only the outside walls. If you want lots of inside walls to make rooms, you’ll need even more Lego!

Wee ones: A Lego brick is shaped like a box. How many faces (flat sides) does it have? Find a box and count them up!

Little kids: If you start building your bedroom wall with 2 red bricks, 2 yellow, 2 blue, 2 green and 2 white, how many bricks is that?  Bonus: If you put 2 8-peg Lego bricks next to each other, how many pegs do you have in total – and how many ways can you place the 2 bricks so pegs line up? (Assume they’re the same color.)

Big kids: The square foot area of a space is the length times the width. If your bedroom is 10 feet long by 9 feet wide, how many square feet do you have?  Bonus: If the two long walls in that 10-million brick house each have 1 million more bricks than each of the 2 short walls, how many bricks are in each wall?

The sky’s the limit: If your bedroom covers 20 square feet, what are all the combos of lengths and widths that it could be (using only whole numbers) — and which combo would need the most length of wall?

 

 

 

 

 

 

 

 

 

 

Answers:
Wee ones: 6 faces – remember to count the top and bottom along with the 4 side faces!

Little kids: 10 bricks.  Bonus: 16 pegs. There are 5 ways to line them up: side by side in a square, end to end in a line, a T (one pointing to middle of the other), and 2 ways to make an L.

Big kids: 90 square feet.  Bonus: 3 million bricks in each long wall, and 2 million in each short wall. Each long and short together use half the bricks – 5 million – and then you need 2 numbers 1 million apart that add to 5 million.

The sky’s the limit: 3 combos: 1 foot by 20 feet, 2 by 10, and 4 by 5. The 1 by 20 will need 42 feet of wall (20 + 20+ 1+ 1), while the 4 by 5 needs only 18 feet (5 + 5 + 4 + 4). The proportions of the space makes a huge difference!

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