Cardboard 1.0
Printer template
Place lens
curved side
down
1.
Print the template
2a.
Glue the template
onto cardboard
Cut out cardboard
3.
Glue light numbers
on top of dark ones
2b.
Assemble as on
g.co/cardboard
4.
MAGNET
Fold this flap behind
the other and affix
the disc magnet
to the reverse side