Math
posted by Daniel .
Bob and his dad visited the hardware store on Saturday. They observed the following transactions:
Mr. Harris bought 4 for $0.50, Mrs. Clarke bought 21 for $1.00, Mr. Montaro bought 1,134 for $2.00, and Ms. Park bought 450 for $1.50. What were they buying?

With the limited data, it is impossible to tell. Repost with adequate data.

I found out that its like Address numbers or something. I looked it up on google

House Numbers, at 50 cents each. Mrs. Clarke bought the number 21, which is 2 pieces and therefore costs a dollar. Same with the others.