Physical exercise is good for any growing boy to help promote muscle growth. Pushups and situps are a great way for boys to keep muscles strong, however remember that simply doing pushups isn't going to make any unwanted fat vanish.
Also be aware that excessive strength training, such as that at a gym, can actually do more harm then good on children, and its best to wait till your mid teens before lifting weights.
Well Im Actually 8 And i can do 40 pushups but 10 to 20 is pretty good
pushups
It depends if the girl has worked towards her max or not. I know girls who can't do one and girls who can do 30. If you want to do more pushups start with a easier modifed version like "girl pushups" (if you can't do a standard pushup) or just do as many as you can in a workout. Eventually you will be able to do many.
I'd say about 50-75 depending on the weight
A 12 year old should be able to do around 25 pushups in 30 seconds. This is a reasonable answer. Hope I helped you!
5
jogging, pushups, sit ups, bridge, burpies, stair runs and skipping
12
A 11 year old girl should have 3,880 calories a day.
A 10 year old girl should consume 1,000 calories a day!
9
a 12 year old girl should be around 6 stone and a 12 year old boy should be around 6 average 7 stones