(I'm not sure how to explain to my daughter on how to do this problem.) The actual length of a machine part is 40 in. The length of the machine part in a scale drawing is 5 in. Find the scale of the drawing.

Question

(I'm not sure how to explain to my daughter on how to do this problem.)    The actual length of a machine part is 40 in. The length of the machine part in a scale drawing is 5 in. Find the scale of the drawing.

anonymous · Answer

The scale of a drawing represents the scale length in relation to the actual length. 

$${5 \over 40} : {1 \over x}$$ We can see that x is 8. Therefore, the scale is 1:8

anonymous · Answer

Thank you so much. I wasn't sure if I actually showed her the right way or not. So I needed to ask someone so I new if I was wrong or write as far as explaining it to her.

phi · Answer

Try Khan's site if you want more info. http://www.khanacademy.org/video/find-an-unknown-in-a-proportion?playlist=Developmental+Math and http://www.khanacademy.org/video/ratio-and-proportion?playlist=ck12.org+Algebra+1+Examples