Use the Ellipse tool to create a rectangle using the same colors used for the head. Chibi hands are oversized and this one is also foreshortened because he is reaching out to the viewer, which makes it even larger! Make the rectangle about the size of shape #1 above.
Right click the rectangle and 'Convert to Path'. Change all 4 nodes from Cusp to Asymmetric and you will instantly have a shape that looks like #2.
The fingers are made like shapes #3, 4 and 5 and are placed on top of shape #2 to create the extended fist. Draw each finger shape using the Pen tool. You can draw a sideways U with the Pen set to Freehand or you can use the Pen set to Point-to-Point and draw a sideways V (which I think is easier; see next paragraph). Don't close the path no matter which way you draw the fingers. We don't want a black outline on the left side of the finger shapes.
To draw each finger Point-to-Point, click 3 times to place 3 nodes in a sideways V. Click Apply. Right click the shape to 'Convert to Path'. Select the node at the point of the V, right click and change Node Type to Symmetric. That should round out end of finger perfectly! Now all you have to do is move the 3 fingers onto shape #2 to complete the fist.
