grams
coconut
Grams.
I would describe their weight in grams.
9 is the best estimate whole number
"Kilogram" is not a unit of weight. It's reasonable to expect that a cat might have a mass of four kilograms.
pounds
estimate it
1200-1500kg
2 tons
Reading the label will give you a very good estimate.
hold it and compare it to a kilo
The weight of a standard letter is typically around 5 grams.
The weight that a mouse can lift will depend on its size. It is estimated that mice can lift things that twice their body weight.
6 ounces
the best mouse to keep for a pet is female fancy mouse
4 inches
Put the mouse in a small bag to stop it running away, weigh the mouse and the bag, deduct the weight of the bag and you have the weight of the mouse.