Pls. give me a code of scientific calculator

You caould have a series of buttons for the numbers, +,-,= and so on.
Put code in each button to increment and decrement the total (depending on if they press + or -) and display the total if they click =.
The key is to decalar the total as a global variable at the top on the form's code:
dim total as double

Making it scientific probably means to add exponenets into it, ie powers.
Add another buton called ^.
It would raise the value of total by that power of the next button pressed. ie. 3^3 = 27.
You would also have to handle decimal places.