Xisaab ahaan isirayn waa furfurid: fansaar hal tibix lambar n {\displaystyle n} ururka tirsiimo T = {\displaystyle T=} { 1 , 2 , 3 , 4 , 5 … } {\displaystyle \{1,2,3,4,5\dots \}} sidoo kale waxay yeelan kartaan dhowr tibix ( n = a 0 × a 1 × a 2 × a 3 × … {\displaystyle n=a_{0}\times a_{1}\times a_{2}\times a_{3}\times \dots } ). Tara kasta oo idil waxaa lagu muujin karaa dhibco. Tilmaan ahaan 6 waxaa lagu muujin karaa siyaabahaa ...... ama :::: Tirooyinka u dhigmi kara laydi ahaan ayaa ah tirooyin leh isirro maratal tirada 12 = 6 X 2 = 3 X 4 Raadinta isirka ax + by + ay + bx Furfuris: ax + by + ay + bx = ax + bx + ay + by Xeerka kala hormarinta isugaynta = ( ax + bx) + ( ay + by) Xeerka hormagalinta isugaynta = x(a + b) + y (a + b) Xeerka kala dhigga iskudhufashada ee isugaynta = (a + b) (x + y)