1 to 100 ...

[heartisablack]

alright, so i need to make a pattern that will show "the sum of 1 to 100: it will display the number in which is the total of the numbers from 1 to 100." here's what i tried, it did not work... maybe you someone can help me out ..

Dim p As Double
intp = 1
intw = 0
For intp = 0 To 100
lstDisplay.AddItem intp + intw
intw = intw + 1
Next

[DiGiTaIErRoR]

Sum of 1 to 100?

You mean 100? Or.. 1+2+3.. etc to 100.

(ubound-lbound)+1 = range(count)

[heartisablack]

i mean the second option you gave, 1+2+3 ...ect to 100 ...

what is wrong with my coding?

[sql_lall]

1) You are adding a thing to the list each time, not just the sum at the end.
2) You are not storing the intermediate sums anywhere. I'm guessing you want them in intw, in that case you should have this instead:

intw = 0
For intp = 0 to 100
intw = intw + intp '*****
Next
lstDisplay.AddItem intw

Note that if you want ALL intermediate sums added to the list box, move the .AddItem call to after the line with the *****

[heartisablack]

so it should be 5050?... thanks so much.

[wossname]

101 * 50 = 5050

[heartisablack]

haha so it is right?

[ZaidGS]

if you need the final sum only use
(a+l)*n/2, where
a: is starting value (here 1)
l: is last value (here 100)
n: is count of values ( here 100 too!!!;) )

so
( 100 + 1 ) * 100 / 2 = 5050
just said what has been said before with more detail :)

PS: if you wonder why we use (n) for count, not just simply (l)
this helps with one of two cases (or maye more)
you dont start with 1, ie. sum from 50 to 100, then use
a=50
l=100
n=51 (be aware here)
of even numbers from 0 to 100
a=0
l=100
n=51

[sw_is_great]

use the formula

sum = n(n+1)/2

instead of looping

[heartisablack]

neither of those worked...

[TheManWhoCan]

The sum of an AP up to n terms is:

S = n(2a + (n-1)d)/2

a is the first term, and d is the common difference.

For the sequence 1,2,3,4...99,100:

a = d = 1

So S = 100(2 + (99)1)/2 = 50 * 101 = 5050

[sw_is_great]

TheManWhoCan whats the difference between your and mine formula :

S = n(2a + (n-1)d)/2


here a = d = 1

So S = n(2 + n-1)/2
or
S = n(n+1)/2

isn't this my formula (infact this is a very well known formula of maths)

Anyway urs is a generic one

[TheManWhoCan]

There is no difference between them for this case, I just thought I'd show a general method so that if the thread starter decided he wanted to sum 1,3,5,7,9...,99 he could do so.

[sw_is_great]

Thats kind of you.
:D

[TheManWhoCan]

I'm a kind person:D :D

[heartisablack]

hey could you help me out?

how could i get this:

Private Sub cmdPattern8_Click()
lstDisplay.Clear
Dim a As Single
Dim b As Single
Dim c As Single
Dim i As Single

a = 0
b = 1
intorder = 1
For i = 0 To 24
c = a + b
lstDisplay.AddItem intorder & ") " & c
intorder = intorder + 1
b = a
a = c
Next i
End Sub

to start at 0, rather 1 for the first number?
thanks.