Scientists discovered a large star 400,000 light years from earth. a light-year is about 5,880,000,000,000 miles. what is the distance of the large star from earth in scientific notation?

Ateacher has $80 to buy workbooks. each work book cost $3. if she buys as many workbooks as possible, how much money does she have leftover? a) $2 b) $4 c) $6 d) $8

School has 204 sixth grade students. if the sixth grade is 30% of the total school, how many students are in the middle school?

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )