flash cards

[pablo1]

does anybody know why to determine the number of integers less than 5000 evenly divisible by 15 you have to divide 4999 by 15??? doesnt 5000/15 have the same result?

Also when do we apply the +1 when subtracting two integers... is it when we are trying to determine the number of remaining objects or integers? like 15-5+1=11 not 15-5=10

[mixpanda]

I think you have to do 4999 because you never know if 5000 will throw off the calculation. For example, if the questions asked for the number of integers less than 6000, the answer would be different depending on whether you calculate 5999 or 6000. I think its just another way to trick the test-taker - force them to estimate so that they might make an error later by forgetting that they estimated.