Drawing a cross-section :)

Have a look at the guidance below.
Remember contours decrease by at 10 metre intervals.
1. Mark each end of the black line on the edge of a piece of paper then mark the contours in between- you don't need to mark each one, but you do need to count how many there are to work out the value of the contour.
For example, the first cross section, toward the mouth of the river. The start of the cross section (to the west) has a value of 50 metres, the next is 40 and so on. Remember if two contours join then they are the same value, so toward the middle of that cross section, to the west of the river are two contours both with a value of 10.
This is pretty tricky to explain, but is best learnt through practice :)
Come and see me Monday if you feel super confused still