Ah, the good old U.S. system of measurement — 8 ounces to a cup, 3 feet in a yard. Learn how to add, subtract, multiply and divide these measures including ‘borrowing’ from larger units and converting to smaller, then converting back in the answer.
There are 20 books in the Pre-Algebra series. The first books continue from the Fraction series with more work on fractions and decimals. Books progress through percentages, proportions, metrics, scientific notation, order of operations and finally, probability in Book 20. Students who complete the Pre-Algebra series are now fully ready for Algebra (coming soon).