One grain of sand weighs 7 x 10^-5 grams. How many grains of sand are there in 6300kg of sand

Question

One grain of sand weighs 7 x 10^-5 grams. How many grains of sand are there in 6300kg of sand

Answer 1

6.3 x 10⁶ ÷ 7 x 10^-5 = 0.9 x 10¹¹ or 9 x 10¹⁰

Answer 2

6.3x10³ kg sand x 1x10³ g/kg x 1 grain sand/7x10^-5 g sand = 9x10¹⁰ grains of sand = 90 billion grains of sand.