Calculating the total magnification for compound light microscope

Do I multiply the objective by the oculars?

Also, if the objective includes scanning lens, (4x) intermediate lens, (10x) and high-power lens, (40x) then do i multiply all of these by the ocular which has a magnification of 10x?

Sorry if this question is completely ridiculous. I am just learning about microscopes.

Thanks

Yes. Objective power x ocular power.
4x objective with 10x ocular = 40x magnification
10x objective with 10x ocular = 100x magnification
40x objective with 10x ocular = 400x magnification