The sum of the first six odd numbers is 36.
210
Their sum is 10000.
155
I assume you mean the first three "counting" (ordinal) numbers, which are 1, 2, and 3. The sum is therefore 1 + 4 + 9 = 14.
The sum of the first 500 odd counting numbers is 250,000.
The sum of the first 50 counting numbers, excluding zero, is 1,251.
21
The sum of the first 10 counting numbers (1-10) is 51.
It is 155 greater.
The sum of the first 100 counting numbers (1-100) is 5,001.
The sum of the first 500 counting numbers (1-500) is 125,001.
4990
thousands
The sum of the first six odd numbers is 36.
210
The sum of the first six positive numbers (1 to 6) is 21.