Can you look at a number and tell right away if it’s divisible by another number? Well, it’s pretty easy for 2 – if it’s an even number, it’s definitely divisible by two. Testing whether a number is divisible by five is easy as well. How can you tell?
In this video, I’ll show you some tricks to determine if a number is divisible by 3, 4, 6 and 7 before you start to divide. Some are simple and fast and some are a bit more complex. These can be very useful tricks for working with larger numbers (or just really fun to play with for a bit).
Download Student Worksheet & Exercises
It’s pretty complex to be able to tell if a number is divisible by 7, but I think it’s really neat that there’s a way to figure it out before you actually do the math. What do you think?
Exercises
- Identify the number(s) that are divisible by 2 in the following list.
301, 3645, 3673 - Identify the numbers that are divisible by 3 in the following list.
3981, 430, 4598, 72624 - Which one of the following numbers is divisible by 7
5894, 56723, 17259 - Is 2353740 divisible by 4?
- Which one of the following numbers is divisible by both 2 and 5?10002, 453970, 637385
- A number is divisible of 2 and 3, will it be divisible by 5?
- If a number is divisible by 2 only, will it be divisible by 4?
- Which of the following numbers is divisible by 3?
45769, 25784, 2391 - List any three 3-digit numbers that are divisible by 5.
- List two 4-digit numbers that are divisible by 4.