Teachers, save “How do you subtract within 20?” to assign it to your class.

1. Click the 2. Choose a strategy to solve the problem 17 - 8. 3. Use the tools to show how you solved your problem. 4. Record yourself explaining the strategy you chose. You must use at least 3 vocabulary words in your explanation. *equation / number sentence *difference *subtract / minus / equals *take away *number line *make a 10 *hundreds grid *quick pictures *count back *related facts (fact families) 5. To submit your work.