Ok so remember
x^n means x times itself n times
example
x^2=x times x
x^4=x times x times x times x
so
a^3
a=7
a^3=a times itself 3 times therefor
a^3=a times a times a
subsitute 7 for a
7^3=7 times 7 times 7
7^3=343
That would be rounding the number to the nearest hundred-thousand.
example: 1,462,924 rounded to the nearest hundred-thousand would be 1,500,000