a+308-1654 =1854
3200+308-1654= 1854
+3200 -3508
308 1654
________________
3508 1854
5.3200:40=400
3200 16000:40=400
.5
_________
16000
a+3208-a=3208
3200
+
3208
______
6408
—
3200
_____
3208
a:40-60=20
3200:40=80
80-60=20