Wirth the JOLLY math pencil calculating becomes that easy! Every pencil consists of two different leads: one graphite lead and one coloured lead (red, blue, green). The graphite lead is used for 1 digits, the colored lead for 10, 100 and 1000 digits as well as for arithmetic symbols. Simply turning the pen around maintains the flow of writing as well as concentration. Like all JOLLY pencils, the math pencils feature an ultra strong wooden encasing and a break-resistant lead.