A sign painter paints individual numerals for a row of 50 houses. The houses are numbered with consecutive integers from 1 to 50. How many 9s are painted?

Answer: 5

List out the numbers from 1 to 50. Then go through that list and circle any numbers that have 9 in them. Those numbers are:

9, 19, 29, 39, 49

So there are 5 houses with 9s painted