When I take the product of even integers from 2 to 40 in R, adding small numbers to the product doesn't appear to change the number.
So, getting that value with a for loop:
sum <- 1
for (i in 1:20){
j <- i*2
sum <- sum*j
}
> sum
[1] 2.551083e+24
Then, when I add numbers, the logical equivalence operator tells me the number isn't changing, e.g.
> sum == sum + 1
[1] TRUE
> sum == sum + 1e3
[1] TRUE
> sum == sum + 1e8
[1] TRUE
> sum == sum + 1e9
[1] FALSE
Why does this happen?
