Housed in what used to be an old village school, Abacus was established over 20 years ago in Clearwater Bay, Sai Kung. In 2004, ESF took over the operations of the kindergarten, refurbished the site and re-opened the school as ESF Abacus International Kindergarten. The school has 194 children and a total of eight classes, four in the morning and four in the afternoon.