Simon’s geometric calculator for +, -, ×, ÷ and √
To add a + b, start at a on the plus scale. Then move b units. You’ll end up at a + b.
Category: Math Tricks
New Friends. New Horizons.
Thanks to the lock-down, Simon’s got new friends. For a little over a month now, he has been part of exciting daily discussions, challenging coding sessions and just playing together … Continue reading New Friends. New Horizons.
Calculating √2
Mom, I’ve tried the ancient Babylonian method and got 0 digits of precision after four iterations. Then I tried the continued fraction method and got four digits of precision after … Continue reading Calculating √2
The Formula for Pentagonal Numbers
A pentagonal number extends the concept of triangular and square numbers, but the patterns involved in the construction of pentagonal numbers are not rotationally symmetrical. The nth pentagonal number pn is the number of distinct dots in … Continue reading The Formula for Pentagonal Numbers
Corona Math
On March 17, Simon started a series of math and coding projects about COVID-19. The first projects he called Corona Math: Why Social Isolation? This is part I of my … Continue reading Corona Math
Pi Day 2020
This year’s Pi Day wasn’t as joyful as in the previous years, as it coincided with our first week in self-isolation and we were too preoccupied to make sure we … Continue reading Pi Day 2020
Some more math tricks
Sometimes, Simon loves a trick or a puzzle so much he writes it down several times over the course of a couple of days. he also really enjoys teaching this … Continue reading Some more math tricks
Mind Your Decisions
For over a month, Simon has been fascinated by Presh Talwalkar’s channel Mind Your Decisions. The channel is full of short videos on famous math problems, logic riddles, proofs and … Continue reading Mind Your Decisions
Alternating series, a crafty solution.
Simon learned this from an alternating series visualization by Think Twice.
Area of a dodecagon without trigonometry
Simon learned this from a visual mathematics video by Think Twice.
Simon’s Formula to Check Triangle Numbers
Simon spent the morning of December 5 pondering about how to test whether a number is a triangle number. “To test if something is a triangle number: double it, ask … Continue reading Simon’s Formula to Check Triangle Numbers
Geeks out of the box 