Since a Baseball cap weighs less than one kilogram, using grams would better. For example 120 grams, as opposed to 0.12 kilograms.
Kilogram
Kilograms!
kilograms
Grams
I would describe their weight in grams.
kilograms
Kilogram
Kilograms!
kilograms
you can't use kilograms to measure a orange, but you can use grams.
grams
Grams
You would measure a boy's weight in kilograms. Grams are more suited for measuring small, lightweight items.
grams
You would typically measure an encyclopedia in grams, as kilograms are typically used to measure heavier weights. A typical encyclopedia would not weigh enough to be measured in kilograms.
I would describe their weight in grams.
kilograms because grams are smaller than kilograms.