[Music] in this video we're going to take a look at conversion graphs which allow us to convert between one unit and another like between miles and kilometers or pounds and dollars if we consider the relationship between miles and kilometers we'd need a graph like this that has miles on one of the axes in this case the x-axis and kilometers on the other axis then to show the actual relationship between the two we'd have a straight line that starts from the origin the main use of graphs like this is to help us convert between the units for example let's imagine that we were asked how many kilometers are there in 30 miles to answer this the first thing we need to do is find 30 miles on our x-axis once we've done this the next thing is to draw a vertical dashed line upwards until we hit our main line and then we draw a dashed horizontal line across to our y-axis and see where it hits which in this case is around 48 kilometers so this tells us that 30 miles is equivalent to 48 kilometers let's try another question a lion walked 75 kilometers how many miles did he travel so this time they're basically asking us to convert 75 kilometers into miles so first of all we need to find 75 kilometers on our y axis and then we draw a dashed line across to our main line and then we draw a vertical dashed line down to our x-axis which hits it at about 47 so we know that 75 kilometers is equivalent to 47 miles which means that the lion walked 47 miles now sometimes you might be asked to work out a value that isn't on your graph for example how many kilometers are there in 500 miles 500 miles is way off our graph because we only go up to 60 miles so to do this we're gonna have to work out the conversion for a smaller number of miles first and then scale it up for example using our graph we can tell that 50 miles is equivalent to 80 kilometers so if we want 500 miles which is 10 times more than 50 we can just multiply the 80 kilometers by 10 as well to find that 500 miles must be equivalent to 800 kilometers anyway that's everything for this video so if you enjoyed it then please do tell your teachers and friends about us and thanks for watching