We may never know what inspired nine-year-old Mary Ann Sadler to convert her mathematics equation into embroidered form. The problem is worked on the basis of the British monetary system using British pounds, shillings, pence (pennies) and farthings. Mary Ann was a student at St. Mark’s School, which was located next to St. Marks’s church on North Audley Street off of Grosvenor Square, near Hyde Park. The school opened in 1831 with the goal of providing the poorer children of the parish with an education at the elementary school level, and it operated in the original building until 1904.