Arătati ca nr 2016 poate fi scris ca suma a 7 nr consecutive naturale

1+2+3+4+5+6+=21
2016-21=1995
1995:7=285 primul
285+1=286 doi
285+2=287trei
285+3=288 patru 
285+4=289 cinci
285+5=290sase 
285+6=291 sapte

a+(a+1)+(a+2)+(a+3)+(a+4)+(a+5)+(a+6)= 2 016
7×a+ 21 = 2 016
7×a = 2 016-21
7×a = 1 995
a = 1 995 : 7
a = 285
(a+1)=286
(a+2)=287
(a+3)=288
(a+4) =289
(a+5)=290
(a+6)=291

Verificare:
285+286+287+288+289+290+291 = 2 016

Numerele consecutive sunt:
285; 286; 287; 288; 289; 290; 291.