Laptop keyboard as a calculator

Hello,
I have a laptop. This is different from the desktop that I have used for several years. The keyboard has a different layout. I have spoken to Dell support and the advise was to "google" and search for I needed an advanced software troubleshooting and reconfigeration of the settings.

When looking at my keyboard, on the lettters : J, K, L, U, I, O, and M, there are numbers imprinted on those keys. For instance, J has 1, K has 2, L with 3, U holds 4, I with 5, O is 6, and M holds a zero. Are you with me? Ok. I would like to configure my laptop to be able to use those keys like an adding machine. I used to be an auditor and prefer using the adding machine mode rather than the numerical keys given on all computers at the top. Can anyone help me? I really would appreciate someone explaining this process in simple English. Thanks for your time!