Engaging lessons that nurture mathematical thinking and help your student advance in addition and subtraction up to 1,000,000, as well as multiplication and division with larger numbers; continue work in fractions; introduce decimals; and provide a hands-on investigation of both metric and US standard measures, including measures of area, cubic measure, and volume. Simply Charlotte Mason product: https://simplycharlottemason.com/store/the-charlotte-mason-elementary-arithmetic-series-book-4/