## Reflection: Student Ownership NO FLIPPING SUBTRACTION - Section 2: Word Problems

Why was I excited enough to title this section "YEAH"? Because when students were given the word problems and a blank sheet to draw base ten blocks for subtraction, along with a NO FLIPPING poster, I only saw one case of flipping the digits in the entire class. That means that 19 students did 10 problems each for a total of 189 done with out flipping. That is an amazing improvement over what I had been seeing.

I do not know if it will continue to carry over into their work, but I do know that they now have a reminder to help them remember that a flipped number in subtraction is not the same equation. They have used drawings and manipulatives to help them see that they can not take 9 away from 6 and still have any left over.

I will keep the posterflippingposter.doc reminding students not to flip hanging in the front of the room. Each time we face subtraction problems I will ask students what they need to remember? "NO FLIPPING SUBTRACTION!" Hopefully by keeping the idea current, students will begin to internalize the idea that flipping the digits over creates a different problem from the one they were given.

Student Ownership: YEAH

# NO FLIPPING SUBTRACTION

Unit 11: The Numbers Are Getting Bigger
Lesson 14 of 15

## Big Idea: Students love the No Flipping Subtraction rule. Can they apply it to word problems?

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Standards:
Subject(s):
Math, Number Sense and Operations, subtraction, solve problems, Word Problem, algorithm
35 minutes

### Beth McKenna

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