Pythagoras Questions

The old “ladder against the wall”, “guy wire supporting a tower” and “distance between two points on a grid” have one thing in common. They are all solved using the Pythagorean triangle formula. A ladder against a wall forms the hypoteneuse (C), with the wall and the distance along the ground forming the other two … Continue reading


Lattice Multiplication

Lattice multiplication may be a way to help those who struggle with long multiplication, particularly those who forget to add “place-keeping” zeroes. This method may look more cumbersome than regular long multiplication but it is actually quite simple. For 32 X 25 you would set up a grid like the one below, separating 32 into 30 … Continue reading

Cover and Calculate – Simple

The speed/distance/time triangle is a classic math construction. Many other equations follow this format. The key to remembering the placement of the letters is alphabetical order. The key to using the triangle is covering the variable you want to FIND with your finger. If you want to find D(istance), cover it and multiply S(peed) by … Continue reading

Around the World in 80 Days

Approximately how many kilometres a day would you have to travel, in order to circumnavigate the globe in 80 days (provided you could travel in a straight line directly on the equator)? a) 891.2796 c) 500 e) 560 g) 15,000 z) 3.14159265359 If you picked “c”, you would be correct. The circumference of the earth is … Continue reading

Cool Cubes

Q.    What do 153, 370, 371 and 407 have in common? A.    153   1 cubed = 1         5 cubed = 125      3 cubed = 27        1 + 125 + 27 = 153   Try this for 370, 371 and 407. Are there any other numbers that are “cool cubes”?

3,4,5 – right?

Have you ever wondered how you can make a perfectly square corner without using a set square? Bricklayers know the trick of the 3,4,5 ratio triangle. Put three bricks at an approximate right angle to four bricks. Use five bricks as the diagonal (hypoteneuse). Shift everything into place. Volia – a perfect right angled corner. The 3,4,5 … Continue reading