A math "trick" that can make subtraction easier:

In my third grade class we called the top method the “Same difference”. The difference is the distance between two numbers, so we just shifted it on the number line like he does.

MCD & mcm

Brilliant!

Brilliant. Thank you.

I'm always on the look out for maths tricks as a grade 4 teacher. I knew the subtracting 1 from each number to remove the zeros but hadn't thought of the other 2. Thank you!

These Twin Puzzles (Gemini Puzzles) from Naoki Inaba make a great class opener to review order of operations and practice critical thinking skills! #mtbos #iteachmath #puzzlingclassroom #logicpuzzle

This math joke. 😂

There is an 18-digit number with the property that moving its last digit up front doubles it value. (Origin: Presh Talwalker?) Find a number such that if you move its last two digits up front (as a pair, keep their order the same) produces double the number.

Some Sunday reading to sink into with another 20 articles from the 2025 TRM Essay Competition Showcase. If you've ever wondered how to win at Risk, how to improve your volleyball serve, or how to mathematically braid you hair, this batch is for you :)