What is the sum of 9260 and 3240?
express your answer numerically to at least three significant figures.

The sum is the result of adding 9260 and 3240 together. Each number can be broken down into constituent parts in order to make addition easier. Each place in the number represents its value, so a 2 in the hundreds place represents 200.
You can separate numbers out this way to make it easier to add them. 9260 can be broken down into 9000+200+60 while 3240 is 3000+200+40. You can then add these six numbers together.

60+40 = 100
200+200 = 400
9000+3000 = 12000

Then add your three partial results together to receive the final

12000+400+100 = 12500