12 <------> 1200
1200 : 12 = 100
12 * 100 = 1200
-----------------------------------
90 <-------> 3600
3600 : 90 = 40
90 * 40 = 3600
---------------------------------
40 <-------> 4000
4000 : 40 = 100
40 * 100 = 4000
---------------------------------
200 <-----------> 180000
180000 : 200 = 900
200 * 900 = 180000