def sum_and_diff(m, n):
    sum = m + n
    diff = m - n
    return sum, diff

# sử dụng chương trình con
a = 5.6
b = 2.3
result = sum_and_diff(a, b)
print("Tổng và hiệu của", a, "và", b, "là", result)

Bài 1: 

uses crt;

var m,n,i,t:integer;

begin

clrscr;

write('Nhap m='); readln(m);

write('Nhap n='); readln(n);

t:=0;

for i:=m to n do 

  t:=t+i;

writeln(t);

readln;

end.

2:

uses crt;

var n:integer;

{---------------chuong-trinh-con-kiem-tra-chan-le---------------------}

function ktcl(x:integer):boolean;

begin

if x mod 2=0 then ktcl:=true

else ktcl:=false;

end;

{--------------------chuong-trinh-con-kiem-tra-duong-am-------------------}

fucntion ktda(x:integer):boolean;

begin

if x>0 then ktda:=true

else if x<0 then ktda:=false;

end;

{--------------------chuong-trinh-chinh-------------------------}

begin

clrscr;

write('Nhap n='); readln(n);

if ktcl(n)=true then writeln('Day la so chan')

else writeln('Day la so le');

if ktda(n)=true then writeln('Day la so duong')

else writeln('Day la so am');

readln;

end.

Bài 1: 

uses crt;

var n,i,s:integer;

begin

clrscr;

write('Nhap n='); readln(n);

s:=0;

i:=1;

while i<=n do 

  begin

s:=s+i;

inc(i);

end;

writeln('Tong cac so trong khoang tu 1 den ',n,' la: ',s);

readln;

end.

Bài 2: 

uses crt;

var n,i,s:integer;

begin

clrscr;

write('Nhap n='); readln(n);

s:=0;

i:=1;

while i<=n do 

  begin

s:=s+i;

i:=i+2;

end;

writeln('Tong cac so le trong khoang tu 1 den ',n,' la: ',s);

readln;

end.

alo

uses crt;

var x,y:integer;

//chuongtrinhcon

function tong(a,b:integer):integer;

begin

tong:=a+b;

end;

//chuongtrinhchinh

begin

clrscr;

readln(x,y);

writeln(tong(x,y));

readln;

end.

uses crt;

var i,t:integer;

begin

clrscr;

t:=0;

for i:=1 to 100 do t:=t+i;

writeln(t);

readln;

end.

uses crt;

var i,t:integer;

begin

clrscr;

t:=0;

for i:=1 to 100 do t:=t+i;

writeln(t);

readln;

end.