Question: Amanda received $50 as a gift. She plans to buy two cassette tapes that cost $9 each and a headphone set that costs $25. How much money will she have left?
Answer with step-by-step thinking: Amanda spent 2 tapes * $9 / tape + $25 = $43. Amanda has $50 - $43 = $7 left.
So the answer is 7.

Question: Michael and Thomas are selling their lego collections. They agree to split any money they earn. They sell them based on how many circles are on top. Each circle costs 1 cent. They earned $5 each after selling 100 single pieces, 45 double pieces, 50 triple pieces and a number of quadruple pieces. How many quadruple pieces did they sell?
Answer with step-by-step thinking: They made $10 because 2 x 5 = 10. They made $1 off single pieces because 100 x .01 = 1. They made $.9 off double pieces because 45 x .02 = .9. They made $1.5 off triple pieces because 50 x .03 = 1.5. They earned $3.4 off the first three types because 1 + .9 + 1.5 = 3.4. They earned $6.6 off the quadruple pieces because 10 - 3.4 = 6.6. They sold 165 quadruple pieces because 6.6 / .04 = 165.
So the answer is 165.

Question: Edith is a receptionist at a local office and is organizing files into cabinets. She had 60 files and finished organizing half of them this morning. She has another 15 files to organize in the afternoon and the rest of the files are missing. How many files are missing?
Answer with step-by-step thinking:
Edith has already organized 60 files / 2 = 30 files in the morning. She has files left to organize so she must still have 30 + 15 = 45 files in the office. This means there are 60 total files 45 organized files = 15 missing files.
So the answer is 15.