HKIMO 2017 Grade 6 National Final (Heat) Set 04 Question 17

A rectangle is cut into 4 equal rectangles. Each small rectangle has area 256 cm². What is the least increase in the total perimeter, in cm, after cutting?

Source glossary (English–Vietnamese): Rectangle: hình chữ nhật; Equal: bằng nhau; Area: diện tích; Perimeter: chu vi; Increase: tăng lên.