# Two simple programs. Help!

I need help with these programs. Truth is, I've never used pascal to program something.

Text:

1. Write a program which will allow you to input 3 digits number and than will calculate and write sum of that numbers.

2.Write a program which will allow you to input natural number N and than will write sum of numbers from 1 to N.

• : I need help with these programs. Truth is, I've never used pascal to
: program something.
:
: Text:
:
: 1. Write a program which will allow you to input 3 digits number and
: than will calculate and write sum of that numbers.
[blue]
First input the number N.

The least significant digit of N will be N mod 10. If you will not be needing N later in the program you can get the subsequent digits by dividing N by 10 using integer division which throws the remainder away, i.e,. N := N div 10.

For example, if N = 123 then N mod 10 = 3, the least significant digit.

Now using integer division N div 10 = 12.

The next digit is N mod 10 = 2

N div 10 = 1

N mod 10 = 1

so the three digits that need to be added together are 3,2, and 1.

[/blue]
:
: 2.Write a program which will allow you to input natural number N and
: than will write sum of numbers from 1 to N.
:
[blue]
The formula for this is

Sum := N * (N + 1) div 2
[/blue]
• : : I need help with these programs. Truth is, I've never used pascal to
: : program something.
: :
: : Text:
: :
: : 1. Write a program which will allow you to input 3 digits number and
: : than will calculate and write sum of that numbers.
: [blue]
: First input the number N.
:
: The least significant digit of N will be N mod 10. If you will not
: be needing N later in the program you can get the subsequent digits
: by dividing N by 10 using integer division which throws the
: remainder away, i.e,. N := N div 10.
:
: For example, if N = 123 then N mod 10 = 3, the least significant
: digit.
:
: Now using integer division N div 10 = 12.
:
: The next digit is N mod 10 = 2
:
: N div 10 = 1
:
: N mod 10 = 1
:
: so the three digits that need to be added together are 3,2, and 1.

:
: [/blue]
: : Ok. I solved the program number 2. But I can't make program number 1 to work. Is there any chance that you post a code?
: : 2.Write a program which will allow you to input natural number N and
: : than will write sum of numbers from 1 to N.
: :
: [blue]
: The formula for this is
:
: Sum := N * (N + 1) div 2
: [/blue]
:

• : : : 1. Write a program which will allow you to input 3 digits number and
: : : than will calculate and write sum of that numbers.

: : : Ok. I solved the program number 2. But I can't make program number 1 to work. Is there any chance that you post a code?

[code]
IN PSEUDOCODE

Sum := 0
for i = 1 .. 3
Sum = Sum + (N mod 10)
N = N div 10
end for
Write Sum
[/code]