Question

a box of medicine tablets contains 200000 tablets each weighing 20mg. what is the total weight of all the tablets in the box in grams and in kg

Answer 1

in mg 
1 = 20mg 
weight 2,00,000 =  2,00,000 x 20 
weight = 40,00,000 mg 

weight in kg = 40,00,000 x 10^-6 
weight kg = 4 kg

Answer 2

200000× 20mg
=4000000mg
4.0000000
4kg