Change range of values in one command button click macro

[DriedMangoes]

Please be nice to me, I'm trying to learn VBA/macros by my own again after 15 years of not doing it

I know this is basic but huhuhu anyway.. I know how to change a value of a cell by a command button, but how do I change all of those values in one click of the command button. See my attached picture.

So I want to change the values of A1:I11 to become less 5% of their original value by clicking the "LESS 5%" button, and by clicking "Original Value", they will return to the original value I placed.

 

[MARK858]

One way...

    Application.ScreenUpdating = False
    Range("K1").Value = "0.95"
    Range("K1").Copy
    Range("A1:I11").PasteSpecial Paste:=xlPasteAll, Operation:=xlMultiply
    With Application
        .CutCopyMode = False
        Range("K1").ClearContents
        .ScreenUpdating = True
    End With

 

[Fluff]

Another way

Sub Less5()
With Range("A1:I11")
   .Value = Evaluate(Replace("if(@<>"""",.95*@,"""")", "@", .Address))
End With
End Sub

 

[DriedMangoes]

Wow I have never encountered this before, it worked, thank you! Would it be okay if I asked what "k1" stands for?
And also, is there a way for the values to return to its original value, say, if I clicked "LESS 5%", 900 would become 855, then if I clicked "ORIGINAL VALUE", 855 would go back to 900. Of course I cannot change "0.95" to "1.05" and create another command as it will only pile on top (as in 900*0.95*1.05).

 

[DriedMangoes]

Hello Fluff, I am years behind with all these stuff so pardon me if I ask silly questions like.. do I replace @ with a range? and what do I put inside the quotation marks?

Another way

Sub Less5()
With Range("A1:I11")
   .Value = Evaluate(Replace("if(@<>"""",.95*@,"""")", "@", .Address))
End With
End Sub

 

[Fluff]

do I replace @ with a range? and what do I put inside the quotation marks?

No, you don't need to change anything. Just run it as-is.

 

[Fluff]

And to add return to the original value try

Sub Add5()
With Range("A1:I11")
   .Value = Evaluate(Replace("if(@<>"""",@/.95,"""")", "@", .Address))
End With
End Sub