Umm well floor(x) returns the highest ingeter <= x. For example:
floor(1) = 1
floor(1.1) = 1
floor(1.9) = 1
floor(2.1) = 2
For example,
Sigma(x=1,3,x+2)
What that says is for all x (integers) beginning at x=1 and ending at x=3, apply the formula x+2 to each of them and return the total. ie:
x=1
1+2 = 3
total = 3
x=2
2+2 = 4
total = 7
3+2 = 5
total=12
So the summation from x=1 to x=3 of x+2 is 12. If you don't really follow that, well now you know why floor and summation are taught in advanced math classes and not in 7th grade
