hello :
let : a the dividend
you have : a = 5×247 + R .... R is the remainder
when divided a by 5 : R = 0 , R = 1 , R =2 , R = 3 , R = 4
R = 0 : a = 5×247 + 0 = 1235
R = 1 : a = 5×247 + 1 = 1236
R = 2 : a = 5×247 + 2 = 1237
R = 3 : a = 5×247 + 3 = 1238
R = 4 : a = 5×247 + 4 = 1239
