How does the magnifiaction of a magnifying glass differ from its magnifying power ?

Explanation

Magnification, `m = ("size image")/("size object") = (v)/(u)` ,
Magnifying power,
`m' = ("angle subtended at eye by image")/("angle subtended at eye by obejct")`,
when both the object and imageare located at the least distance of distinct vision (d) from the eye. `m' = (d)/(u)`.
Clearly, `m ne m'`, unless `v = d`.