Dùng For...to...do:
program BT;
uses crt;
var i,T: byte;
Begin
clrscr;
for i:=1 to 100 do T:=T+i;
write('Tong 100 so tu nhien = ',T);
readln
End.
Dùng While...do:
program BT;
uses crt;
var i,T: byte;
Begin
clrscr;
i:=1;
while i<=100 do
begin
T:=T+i;
i:=i+1;
end;
write('Tong 100 so tu nhien = ',T);
readln
End.