If you wish to sum every number as you go along:
10 LET A=1
20 PRINT A
30 LET B=A+1
40 PRINT A+B
50 LET C=B+1
60 PRINT A+B+C
70 LET D=C+1
80 PRINT A+B+C+D
90 LET E=D+1
100 PRINT A+B+C+D+E
110 LET F=E+1
120 PRINT A+B+C+D+E+F
130 LET G=F+1
140 PRINT A+B+C+D+E+F+G
150 LET H=G+1
160 PRINT A+B+C+D+E+F+G+H
170 LET I=H+1
180 PRINT A+B+C+D+E+F+G+H+I
180 LET J=I+1
190 PRINT A+B+C+D+E+F+G+H+I+J
200 STOP
10 for t = 1 to 50 20 input a 30 c = c + a 40 next t 50 print c
The sum of the first 50 whole numbers is 1,225.
The sum of the first 1,000 whole numbers is 499,500.
The sum of the first 40 whole numbers is 780.
the sum of the first 15 prime numbers is 328 .
The sum of the first 25 prime numbers is 1,060.
The sum of the first 15 odd numbers is 225.
The sum of the first 100 odd numbers is 10,000.
The sum of the first 300 odd numbers is 90,000
The sum of the first 100 numbers, excluding zero, is 5,001.
The sum of the first 40 odd numbers is 1,600.
The sum of the first 250 prime numbers is 182,109.