Now, if you want to calculate the magnifying power of the telescope, just start with the same equation you used for the magnifying lens, but with a negative sign, because the image is flipped.
A magnifying glass (called a hand lens in laboratory contexts) is a convex lens that is used to produce a magnified image of an object. The lens is usually mounted in a frame with a handle (see image).
A sheet magnifier consists of many very narrow concentric ring-shaped lenses, such that the combination acts as a single lens but is much thinner. This arrangement is known as a Fresnel lens.