just add them 1+3+5+7+9+11+13+15+17+19 = 100
or a trick you could use is realize that
19 + 1 = 20
17 + 3 = 20
15 + 5 = 20
13 + 7 = 20
11 + 9 = 20
20 x 5 (total pairings or half the numbers your adding) = 100
2500
The average is 10. You will find that the average when adding together the first n odd numbers is always equal to n.
The first 20 odd numbers are: 13579111315171921232527293133353739.
The first 85 odd numbers are: 1 3579111315171921232527293133353739414345474951535557596163656769717375777981838587899193959799101103105107109111113115117119121123125127129131133135137139141143145147149151153155157159161163165167169.
The sum of the first 1,000 odd numbers is 1,000,000.
algorithim and flow chart of odd number 1 and 50
2500
The average is 10. You will find that the average when adding together the first n odd numbers is always equal to n.
The first 20 odd numbers are: 13579111315171921232527293133353739.
The first 100 odd whole numbers are: 13579111315171921232527293133353739414345474951535557596163656769717375777981838587899193959799101103105107109111113115117119121123125127129131133135137139141143145147149151153155157159161163165167169171173175177179181183185187189191193195197199.
The first 85 odd numbers are: 1 3579111315171921232527293133353739414345474951535557596163656769717375777981838587899193959799101103105107109111113115117119121123125127129131133135137139141143145147149151153155157159161163165167169.
The sum of the first 300 odd numbers is 90,000
The sum of the first 1,000 odd numbers is 1,000,000.
The sum of the first 50 odd numbers is 2,500.
The sum of the first 40 odd numbers is 1,600.
The sum of the first 153 odd numbers is 23,409.
The sum of the first 8,000 odd numbers 64,000,000.