10x10x10x10x10x10=1000000

means 10x10x10x10x10x10
as it's basically saying 10 is multiplied by itself 6 times which gives you 1000000
350 / 28 = 12.5 gallons, so 13 gallons needed
13 X 2.5 = $32.50
The circumference of a circle can be found using the equation 2 π r
(2)(3.14)(4.5) = 28.26 (or 28 13/50 if you need it in fractions)