From the CISCE curriculum. 5 key concepts, about 2 days of study at 20 to 30 minutes a day.
Children in class VI were exposed to and were enabled to understand that algebra is an extension and generalization of arithmetic. Letters for numbers are to be seen as a compact language to express situations in expressions. The basic idea of various terminologies that form the language to learn algebra is also to be communicated to children in a gradual manner. Children should get a feel that algebra is just extension of numbers and quantities. They should also gain fluency in mathematical language through operations on algebraic expressions and solving linear equations.
From the CISCE Curriculum for Classes I to VIII (2016). CISCE sets what is taught, not the textbooks, so schools use different books and there are no page numbers here. Adhian Gurus is not affiliated with CISCE.