What is indicated by S, P and K on the orthophoto map​

Topographic maps have contour lines that connect points of identical elevation above sea level. Contour lines run next to each other. Adjacent contour lines are separated by a constant difference in elevation, usually noted on the map. Topographic maps have a horizontal scale to indicate horizontal distances.

the value of the 4 in the hundreds place is 400 while the value of th e 4 in the tens place is 40

400 is way bigger than 40.