The conversion factor between kilo and base unit which is grams in this question is 1000 so there is 1000 grams in 1 kilogram so first we need to convert kilograms to grams so we multiply by 1000 so 30kgx1000= 30000 grams so to find the number of crayons then we divide by 30 which is the mass of one crayon to find out how many we need so 30000/30= 1000 so you would need 1000 crayons
