Math: Addition and Subtraction book is excellent for adults who need to learn math from scratch. It starts with very simple 1 + 1 addition and moves on to math equations like if x + 5 = 15, what is x? The book is easy to follow and makes teaching an adult learner easy and simple. At the completion of this book the learner will be able to: - determine number place values - round numbers - add single digit numbers - add double digit numbers without carry-over - add double digit numbers with carry-over - add three and four digit numbers with carry-over - subtract single digit numbers - subtract double digit numbers without borrowing - subtract double digit numbers with borrowing - subtract three digit numbers with borrowing - subtract numbers with zeros - basic addition and subtraction equations - using rounding to estimate answers