7,8*1000= 0,00081*1000= 0,006*10 000=
7,8 * 1000 = 7800 0,00081 * 1000 = 0,81 0,006 * 10000 = 60
0.00081x1000=0.81 7.8x1000=7800 0.006x10000=60