That depends on how big it is. They aren't all the same size.
Depends on the math book.
400g
depends what kind
A school backpack should weigh less then 15 % of your body weight.
678tons
1
it ways about 1 kilogram
How much do math middle school teacher make you a year ? Honestly I can not answer this particlar question I really dont know
Roughly 8.5 lbs per gallon. You do the Math.
Mac book air weight is 2.3pound (1.06kg)
just do the math 700 - 227 use a calculator
It weighs 4 kg or 8.8 lbs in high school