# Number Sense Blog

### Mathnasium #MathTricks: Divisibility (Rule for 9s)

Jan 5, 2022

A number is divisible by 9 if the sum of the digits is divisible by 9.
To determine if the number 738 is divisible by 9, we find the sum of its digits. Seven plus three plus eight gives us a final sum of eighteen. Eighteen is divisible by ...

### Mathnasium #MathTricks: Half of Even Numbers (Part 2)

Dec 15, 2021

To find half of even numbers, sometimes it is useful to break apart the whole number into its parts. We can do this to find half of 26.
Since 26 is composed of 2 tens and 6 ones, we can find half of 26 by finding half of 20 and half of 6. Half ...

### Mathnasium #MathTricks: Number Sense (Subtraction Part 2)

Dec 8, 2021

Here is a number sense trick to subtract without borrowing.
Let’s say we want to subtract 54 from 900. Since the digits in the ones and tens places of 900 are both less than the same digits in 54, we need to borrow to find the difference.
Wi...

### December 2021 Math Activity: #NationalCookieDay

Dec 4, 2021

Today is #NationalCookieDay and what better way to enjoy math than to incorporate it into a fun activity like baking cookies? Download our Snickerdoodle Baking Activity and Key, and share your cookie creations on social media! Be sure to tag ...

### Great Gifts for Math Lovers 2021

Dec 1, 2021

The holiday season is upon us, with gift-giving opportunities around every corner! Our annual Holiday Gift Guide can help you find the perfect gift for your favourite math-y people. From books to home-décor and everything in-between, you can’...