What sums add up to 34?

Answer 1

1+34=35, 2+33=35, ....33+2=35, 34+1=35

so 35*34 is

35*34=

(30+5)*(30+4)

30*30+5*4

900+20

920

35*34=920/2=

460

if we add up until 34 th answer is 460