Hello Please could you help me with this question

Find a quick way to add all Intergers (whole Numbers) between 1 and 1000?

I am at secondary school and am 12 years old

Thank you
From Louise

How about 'symmetry':

Add 1 and 1000
Add 2 and 999
Add 3 and 998

Do you see a pattern?
How many terms are there?
[Be careful about the middle term]

Walter Whiteley