In Top view, "Add-Mesh-Circle", with five vertices.
In Front view, enter Edit mode and Extrude four times down. Reshape like
in the image.
In Side view, select all the finger vertices, Copy four times, reshape and
dispose them like in the image.
Select one finger, Copy, Scale, reshape and place it, to make the thumb.
To make the palm, extrude the low row of the arm and scale like the image.
Now you must build Faces to rely the fingers to the palm.
First rely the 4 low fingers. Select the four adjacent vertices of two fingers
and Build a face. Than rely the fingers to the palm (see images below).