Math Quiz!

[acoustic hearth]

if :
Y= 1+2+3+4+5+6+7+9+10+............+1000
so:
Y= ??

[royal basin]

I think I did it, I got 500,500

I need to check it but I think I got it

[onyx zodiac]

^

should be right

1001*500

[finite mantle]

ye

because 1+1000= 1001, going down because 2 and 999 also equal 1001

and 1000 is even so there will be no number left

and 1000/2 (cuz we add in pairs) is 500

and each pair adds up to 1001

1001*500=500500