In this 1835 work, Sarah Porter, née Ricardo (1790–1862) shows her enthusiasm for arithmetic, and her concern for teaching it in a way that will develop the pupil's mind: 'There is no branch of early education so admirably adapted to call forth and strengthen the reasoning powers.' She uses the device of a conversation between pupil and teacher, popularised by Jane Marcet (several of whose works are reissued in the Cambridge Library Collection), to guide young Edmund from the written symbols for numbers through addition, subtraction, multiplication and division, fractions and decimals, proportion, and square and cube roots. Answers to the questions are provided at the end of the book. A member of the Central Society of Education, which promoted imaginative theories of education instead of rote learning, Mrs Porter reworked her book in 1852 as Rational Arithmetic, a more conventional and less entertaining textbook for use in schools.