This spec, by itself doesn't really tell you enough to actually compare. What they are doing is taking the longest focal length of the lens, 357mm, and divide it by the shortest focal length, 4.3mm, you get 83X. This camera also gives you an equivalent focal length of 24mm to 2000mm. This is not really 24mm to 2000mm, but since the sensor is so small, the camera produces an equivalent field of view on the sensor of what you would see on a full frame camera of 24mm to 2000mm.

Now lets consider a full frame camera for which you have several lenses. Lens 1, let's suppose is 24mm to 70mm. Lens 2 is 70mm-200mm, and lens 3 is 150-600mm. Now, to get this range, you have to use 3 lenses. But the magnification could be computed as 600/24 = 25x. But now, you decide to add a 15-30mm lens. Now the 4 lens power is computed as 600/15 = 40x.

Notice, we did not increase the max focal length, but we did increase the power from 25x to 40x by changing the widest focal length.

So we see that the power, by itself, only tells us the ratio of longest to shortest focal length. And we can change that number by reducing the wide end or increasing the long end.

Now let's do some more math. 24 divided by 4.3 is 5.58. And 2000 divided 357 is 5.60. Rounding both to 5.6 tells us that whatever the actual focal length is, we multiply it by 5.6 to get the equivalent focal length. This in turn affects what the final image is going to look like as we start to enlarge it. The full frame will look better.

42X, 83X and 100 X compared to what? We can start with the mathematically correct "standard" normal 35mm figure of 43.3mm or the commonly accepted 50mm. Also, factor in that smaller sensors' crop factors are rounded and published focal lengths vary, and you have a myriad of numbers with which to deal.

To simplify matters, using the common 50mm "standard", a 70-300 is 1.4X to 6x.

Of course, the science of optics, combined with the design of lenses, gives us so many variables that the answer to your question can only be approximated. By the way, I like your spelling of lense; it drives some people absolutely insane. 😊🙃🙂