Everyone's stomach is as big as their own hand.
7-9 year olds use a 11inch ball 10-12 year olds use a 12inch ball
Depends, I guess. :)
Small
Whatever size it happens to be, they are all different.
roughly 8.8"
Try Nerf footballs
13 inches
Between the ages of 10-12 the average size of a male brain is 1,440 grams and the average size of a female brain is 1,260 grams. The size of a nine year olds brain is only slightly smaller.
About in a girls size, a 4. In a boys size, a 5.
12" balls i believe
about the girl hand size would probably be 19mm for 18 yr olds and about 13mm. for 10 yr olds.
A 4/4 cello is a full size, usually 12-13 year olds to 30-40-50 year olds depending on how big you are.