Step-by-step explanation:
4 x 103 = 412, 3 x 104= 312
412 x 312 = 128,544
number has to be between one and ten and show significant digits. the decimal has to be moved five tome to the left creating the number 1.28544. to move the decimal back you have to multiply by 10 to the 5th power. Yielding 1.28544 x 10^5
