This workbook contains 39 printable pages to help your students add and subtract two, three and four-digit problems. You will find a progression from simple to complex: from two digits to three digits to four digits; from no regrouping to regrouping; from one zero to two zeros to three zeros; from a zero in the ones place to the tens place to the hundreds place; from two numbers to three numbers to four numbers in a column. Lessons are organized from...