We will draw a sketch for a 10 × 10 cm base.

We will use the Extrude tool to create a thickness of 3 mm .

We will use the same two tools to create a recess in this square so we can place the other sides into it. 

We will draw a sketch to create the sides of the box, and we’ll add a tab so it can fit into the slots in the base. 

We will make their thickness 3 mm as well 

We will convert them from bodies to components and assign a wood material to them. 

We will apply joints so they fit together.

After all the sides are joined together, the box is complete 

We will create a cutout halfway to make it easier to pull out the paper .

We will start sketching a section to hold the pens. 

We will use Extrude to give it height. 

We will hollow it out so we can place the pens, and then draw two rectangles with a 3 mm length to fit it into the box. 

We will extrude it so it can fit into the box. 

We will extrude it so it can fit into the box. 

We will also apply a joint so it fits in place like in the picture.