Question

How to teach conversion from meters to kilometers, milliliter to liters grams to kilograms

Answer 1

METERS TO KILOMETERS= 1*100
MILILITRE TO LITRE=1*1000
GRAMS TO KILOGRAMS=1*1000

Answer 2

meters to kilometers = the given no. have to multiply with 1/1000. process is in below
1 km = 1000 m 
1 m = 1/100 km

millilitres to litre = the given no. have to multiply with 1/1000. process is in below
1000 ml = 1 l 
1 ml = 1/1000 l

grams to kilograms =  the given no. have to multiply with 1/1000. process is in below
1000 gm = 1 kg
1 gm = 1/1000 kg