Please help! Giving braniest to the quickest answer!

The volume of the material in the cracker is

(volume of the outer cylinder) minus (volume of the cylindrical hole)

The volume of any cylinder is

V =  (π) (radius)² (length)

For the outer cylinder:

V =  (π) (8 mm)² (18 mm)

For the cylindrical hole:

V = (π) (4 mm)² (18 mm)

The solid material in the whole cracker:

V =  (π) (8 mm)² (18 mm)  -  (π) (4 mm)² (18 mm)

V = (π) (18mm) {(8 mm)² - (4 mm)²}

V = (18π mm) (48 mm²)

V = (18π · 48) mm³

V = 2,714.3 mm³

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.