You can weigh it either way, the only difference is a factor of 1000 in the result.
it weigh 1 kg
You would weigh a baseball bat in kilograms.
I think it is kilograms
290kg
10 kilograms
It would actually weigh about 500 grams and it would not be very practical if your cereal box weighed more than you
You could (theoretically) use either... However - Kilos is the preferred measurement.
Grams
kilograms because kilo means 1000
kilometer
Grams and kilograms are measurement of weight. For a letter you would use grams. For a package you would use kilograms as it weight is more.
it is 350
35 grams!