Rounding numbers to estimate the sum 256+321

Pam buys a sleeve of ball bearings for her skateboard. each of the bearings is 1 1/5 inches wide. the sleeve is 9 3/5 inches long. how many ball bearings are in the sleeve? show your work.

Which of these numbers of simulations of an event would be most likely to produce results that are closest to those predicted by probability theory? 15, 20, 5, 10

Of of at a : $6, $8, $7, $6, $5, $7, $5, $7, $6, $28, $30 is?ato .ato .ato .ato .