Pascasio, Mike S. Teaching odd and even numbers using number pyramid/ Mike S. Pascasio. - Philippines: In the Grade School, Inc., c2010-2011. - v59 n4, page 164: illustrations; 28 cm. ISSN: 2094-8042 Subjects--Topical Terms: Mathematics. Dewey Class. No.: DPer 370.105 M72 June 2010-Mar 2011 v. 59 n. 1-10