This interactive SMARTboard lesson is a complete lesson in rounding numbers to the nearest ten and to the nearest hundred. It can be broken into several mini lessons followed by practice in each of the skills. It begins with a definition of what it means to round numbers. Diagrams of number lines help explain the steps in rounding numbers to the nearest ten and hundred. Lesson increases in difficulty as teaching aids are withdrawn so that students are rounding a hundreds number to the nearest ten without any additional clues. Created with Smart Notebook 11. MUST have SMART Notebook software to download and use this lesson.