Free Printable Number Line to 20 PDFs - Freebie Finding Mom While the two printable integers number lines up to 20 above are great, they don't actually include any math problems. (Although, you could create your own by writing on the printables.) However, this number line to 20 worksheet includes easy addition problems so your child can practice his or her number line knowledge. If you want to allow your kid to also practice subtraction or even multiplication, simply re-write some of the plus signs on the number line to 20 worksheet.