Convert the scientific numbers to standard form:
1.2 x 10^3 = 1,200
3.9 x 10^2 = 390
2.1 x 10^2 = 210
Volume = 1200 x 390 x 210 = 98,280,000 cubic mm
Now convert standard form to scientific form by moving the c=decimal to the left and counting the number of spaces it moved.
Scientific notation:
98,280,000 = 9.828 x 10^7 ( a = 9.828 abd b = 7 )
Standard form:
98,280,000 cubic mm