<p>Teaching ELLs To Use Word Parts to Uncover The Meaning of Math Words: PREFIX DEFINITION EXAMPLE bi- cent- circum- co- dec-, dek- hemi- in- inter- iso-, is- mid- nona- oct- par- PREFIX DEFINITION EXAMPLE pent- per- poly- quad- semi- sept- SUFFIX -gon -hedral -hedron -lateral -metry -sect PREFIX DEFINITION EXAMPLE bi- two biweekly, bilateral</p><p> one hundred, one hundredth centimeter, century, cent- centipede, Centigrade</p><p> around circumference, circum- circumnavigate co- joint, jointly, together coplanar, cohesive dec-, dek- ten, tenth decibel, decimal hemi- half hemisphere in- not, without inequality, insufficient inter- between, mutual intersection, interview iso-, is- equal isosceles triangle mid- middle midpoint, midway nona- ninth, nine nonagon oct- eight octagon, octave par- beside, alongside parallel PREFIX DEFINITION EXAMPLE pent- five pentagon per- for each percent poly- many polygon, polyglot quad- four quadrilateral semi- half semiannually sept- seven septennial SUFFIX</p><p> figure with a given number of polygon -gon interior angles</p><p> surfaces or faces of a given dihedral, tetrahedral -hedral number</p><p> figure having a given number polyhedron -hedron of faces or surfaces -lateral of, at, or relating to sides equilateral -metry science or process of measuring geometry -sect cut or divide bisect</p><p>Anita Bright, Fairfax County Public Schools, TESOL 2006</p>