Question

1+2+3+4+........52+53

Answer 1

1+2+3+4+...+52+53=
=53×54:2=
=2862:2=
=1431

Answer 2

$1 + 2 +3 + ... + 52 + 53$
Prin metoda sumei Gauss, obtinem

[53 (cate numere sunt) × (53+1) (suma dintre primul si ultimul numar)] ÷ 2

deci (53 × 54) ÷ 2

ce devine

$53 \times 27 = 1431$