Math Is Fun Forum

Hello,

Matrix subtraction is a legal operation but the elements needs to be same in both the matrix. for eg a @*2 matrix can be substracted only from 2*2 matrix and not 3*3 matrix.

We also have a divisibility test for 6 and 9.
For a number to be divisible by 6, it should be divisible by both 2 and 3.

Example:
like 18 is divisible by both 3 and 2 so it is divisible by 6.
For a number to be divisible by 9, its sum of digits must be equal to 9.

Example:

like 18 , here sum of the digit is 1 + 8 = 9, so it is divisible.

I know its not really tough but I just found it interesting.

I just love playing with numbers . Basically series, its is so amazing that every number series has a solution to it. Just think carefully  and it will be solved.

Hello,

I cannot understand how are you getting these results. Please elaborate.

Thanks

Thank you all for welcoming me.
Maths is a subject that needs practice but if you take it as a burden, you will never come out of the fear of numbers. Just make sure that you practice maths daily but too much of practice will also not be a good thing

All the best