Plus 12345+1000-2 =13345-2 =13343 Minus 1003-998 =(1000+3)-(1000-2) =3+2 =5 Square 998^=? (998+2)*(998-2) (1000*996)+4=996004 251^2+?=252^2 251-->252 : 251+251+1 =250+250+3=503 15^2+?=16^2 15-->16 : 15+15+1 =31 The change in volume in a triangular pyramid if a radius is 98 For example, - The area of a circle with a radius of 98 - The area of a circle : πr^2 --> π98^2 Geometric progression Exampl..