one grain of sand approximately weighs 7 x 10 to the power of -5g how many grains of sand are there in 6300kg of sand give answer in standard form

Question

i don't know how to work it out

Answer 1

[6300 kg x (1000g/1kg)]/(7 x 10^-5 g/ grain) =

6300,000g/ (7 x 10^-5 g/ grain) =

6.3 x 10⁶/7 x 10^-5 = .9 x 10¹¹grains =

9.0 x 10¹⁰ grains