2. Subtraction Elizabeth Johnston

3. Nail Abacus 57-34= Students place 5 washers on the tens nail Students place 7 washers on the ones nail Students are then either instructed to “take away” 34 or remove the know addend from the sum. Students then take 3 washers off the tens nail and 4 washers off the ones nail. Answer: 23

4. Nail Abacus 57-39= Students place 5 washers on the tens nail Students place 7 washers on the ones nail Since students cannot take 9 washers from 7 washers, students must take 1 washer off of the tens nail and place 10 washers on the ones nail. Now students take 9 washers from the ones nail and 3 washers from the tens nail. Answer: 18

5. Number Line 14-8= Provide a number line for each student. The student is taught to start at 14 and move eight spaces to the left (negatively). Where the student ends is the answer. Answer: 6

6. Addition-Subtraction Pattern 47+23= 70 70-47= 23 70-23= 47

7. Self-Monitoring Subtraction Strategy 1. Begin? In the 1s column. 2. Bigger? Which number is bigger? 3. Borrow? If the bottom number is bigger, I must borrow. 4. Basic Facts? Remember basic facts. Use drawings or touch math if needed. Student uses these to match up with cue words on a worksheet.

8. Self-Monitoring Example