In this lesson, students apply knowledge of place value to add and subtract numbers up to 1,000. Using sentence frames and place-value disks, they relate 100 more, 100 less, 10 more, and 10 less to addition and subtraction. For example, 290 - 100 is 2 hundreds 9 tens minus 1 hundred. Students record the addition and subtraction of multiples of 100 using arrow notation