One of the key shifts to the Common Core is the focus on problem solving. Even in first grade, students are expected to be able to solve all kinds of addition and subtraction story problems, with the unknown in all locations. This culminating story problem has students apply their understanding of separate change unknown problems to larger numbers and also to a complex number set. Students have to apply their understandings of base 10 (particularly the idea that a ten is a bundle of 10 ones), which sets them up to understand regrouping in later grades.
Review Past Learning:
We have been learning about all kinds of problems, and talking about where the missing part is. Today we are going to apply everything we know to this Peter Rabbit story!
Connect to the Real World:
This is important because in 2nd grade, 3rd grade, and all the way through school, you will encounter so many kinds of math problems. You know how to read the problem and show how to solve it-this will help you for all your future math problems!
Your thinking job today is: Where is the unknown number and how can I solve for it?
Students work to solve at their desks for 10 minutes. Students have base 10 blocks available for solving. I am circulating to see what strategies students are using. I am particularly looking for what strategies I want students to share. In this case, I chose 2 students who showed different ways to take from 48 and get to 29.
My Story Problem pdf for students is attached!
I'll bring students back together and have the 2 students I already selected share their strategies with the class. The focus of the strategy share is so all other students access a variety of strategy types, exposing them to strategies they could use to solve similar problems later.
While students share their strategies, I am scribing the representation. This representation provides a mental road map for students to represent their own thinking, and for students who want to try this strategy later to revisit and follow. See the Strategy Chart I wrote as students shared their strategies.
Watch the attached Strategy Example to see how one student solved and showed the class her strategy!
Guiding Questions (after the strategy share):
To cap off this unit, students will do the attached assessment. It assesses 1.OA.1, 1.OA.D8, and 1.OA.C6. It also has a timed fluency portion for 1.OA.C6.