Halit Sen, who graduated from the Gazi Educational Institute and started his career as an English Teacher in Konya College in 1972, has 43 years of experience as an educator. He continued his profession abroad between 1983-1990. He was the co-founder, director and training coordinator of Metro Language Center from 1990 to 1995. Afterwards, he was hired by Mersin University and worked in the department of foreign languages as an instructor and assistant director until September 2005 when he retired and went to Saudi Arabia to join Jubail Industrial College, where he worked for more than two years as instructor. He returned to Turkey towards the end of 2007. During these two years, he studied the scientific grounds for abacus-based mental calculation programs. He then travelled to Far-east to further explore abacus-based mental calculation and brain development models, where he successfully completed trainer program in CMA Institute and received Dual-Hand Abacus Use and Mental Calculation Skills Certificate, after which he returned to Turkey and established Menar Mental Arithmetic Center in Mersin in March 2008.

The Founder's Publications

Halit Sen has Master's Degree in English Linguistics from the Institute of Social Sciences, University of Mersin. His dissertation and other books are as follows:

• Work on Your English (with Oya Katirci, Technical English coursebook for Vocational School Technical Departments:2002)
• An Evaluation of Language Origin Theories from the Viewpoint of Cognitive Linguistics (Master Dissertation: 2003)
• English At Work (with Remzi Gulsun ve Hakan Sen , Vocational English coursebook for Vocational School Technical Departments: 2003
• The New Light (with Prof. Dr. Ayhan Sezer and Remzi Gulsun), English Coursebook for university students: 2005
• Menar Program Coursebooks (2008):
• Basic Abacus
• Abacus 1, Abacus 2, Abacus 3, Abacus 4, Abacus 5
• Introduction to Abacus
  
• Menar Abacus Mental Arithmetic Thresholds
  

Some of the diplomas and certificates Halit Sen has received throughout his career:

• Gazi Educational Institute, English Teaching Diploma (1972)
• Anadolu University, Licence Completion Diploma (Bachelor's Degree) (1993)
• Mersin University, Science Specialist Diploma (Master's Degree) (2003)
• Barcelona University, Computer Applications for Language Teachers Certificate (1988)
• Barcelona University, Language Testing Certificate(1988)
• Columbia University Robert F. Mager Associates, Classroom Presentations Skills Certificate (1988)
• Taiwan CMA Institute: Dual Hand Abacus Use and Mental Calculation Skills Certificate (2008)

Halit Sen is married with two children.