help with these 2 questions

Question

1, Estimate the number of pencil cases needed to hold 10 thousand pennies. Show your work.
2 Estimate the height of a stack of 50 thousand pennies. Show your work.

Answer 1

We can't do the first problem without knowing the size of a pencil case.

A penny's thickness is 1.55 mm and its diameter is 19.05 mm.

2.
50,000 * 1.55 = 77,500 mm = 77.5 m

Answer 2

Thanks im not in ur class but this helped :)