6.0 Rujukan

Murugiah s/o Velayutham & Kao Thuan Keat (2010), HBMT2103 
        Teaching Mathematics in Year Two. Meteor Doc. Sdn. Bhd, 

        Selangor Darul Ehsan.

Piaget-Stage 3-Concrete-Reversibility diperolehi daripada
       http://www.youtube.com/watch?v=gA04ew6Oi9M&feature=related
       pada 20 November 2010.

Lee Tak Sing, Lean Kee Fong & Azizah Binti Tengah (2003),
       Matehamtics Year 2 Text Book Part 2. Hypersurf Corporation Sdn.
       Bhd. Kuala Lumpur.

Lee Tak Sing, Lean Kee Fong & Azizah Binti Tengah (2003),
       Matehamtics Year 2 Activity Book Part 2. Hypersurf Corporation
       Sdn. Bhd. Kuala Lumpur.

Curiculum Development Centre (2004), Mathematics Year 2 Teaching 

       Courseware Unit 6-7 Lessons 95-110, Ministry Of Education
       Malaysia.