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