Progression of Skills - Strategies to Add and Subtract within 20

Before this lesson:

Students should be fluent in understanding and demonstrating the relationship between numbers and quantities of 0-20, demonstrate addition and subtraction within 10, count within 10, and use and understand subtraction as taking away or removing. If a student can complete this Readiness Check! activity with little to no help and with ease,  they are ready for this toolkit lesson.

Students Do:

Start with 10 toy cars, adds 2 more from a friend, totaling 12. Later, the child shares 5 cars, leaving 7. Counting on, they realize they need 3 more to have 10 again, showcasing an understanding of numbers, addition, subtraction within 10, and the concept of taking away.

This Toolkit Lesson:

focuses on using the making a ten strategy to solve addition and subtraction number and word problems within 20.  Students will use the ten-frame and 5 group models to represent their thinking and problem-solving. 

Students Do:

The child has 16 chocolate chips and needs to distribute them equally into bags. They use the "make a ten" strategy by realizing they can take 6 chips from 16 to make a ten and a leftover 10. They easily divide the chocolate chips into two bags of ten and six.

After this lesson:

Students will move away from the concrete to the abstract using a number line to practice addition strategies by counting on by making a ten and subtraction strategies by removing or counting on. 

Students Do:

Students should continue to practice mental strategies and know from memory all sums adding two one-digit numbers. Try this resource!