To find the mean (average), u add up all ur numbers, then divide by how many numbers there are.
mean = (5 + 12 + 1 + 5 + 7) / 5 = 30/5 = 6
To find the mode (and there does not have to be one)...u find the number that is used the most. That number would be 5...because it is used twice, whereas, the other numbers are just used once.
Well there are no specific numbers, but the area of a rectangle is the length x the width, and the width is the area ÷ the length.
Some expressions are:
7 times 4 equals 28
20 plus 8 equals 28
10 plus 18 equals 28
25 plus 3 equals 28