Reflection: Connection to Prior Knowledge Adding and Subtracting Mixed Numbers - Section 2: Launch


I know from teaching this is the past, students have a hard time with subtracting mixed numbers.  Prior to this, I have taught those students who struggle to just change the mixed numbers to improper fractions and then subtract, then change them back to mixed numbers. 

This year I choose to try something that gets at the understanding this concept.  I used more modeling, number sense, and connections to prior learning. 

Students regroup when they add and subtract all the time.  Over time, they have moved away from really focusing on the meaning of these procedures and more towards automaticity.  By taking a little time to uncover this prior learning, students are able to connect regrouping fractions into wholes with regrouping ones into tens etc.  

Yes, this is a complex skill because there are many components for solving just one problem, they still need additional practice. But I feel this was a more meaningful approach.  

  Transition student thinking from something old to something new
  Connection to Prior Knowledge: Transition student thinking from something old to something new
Loading resource...

Adding and Subtracting Mixed Numbers

Unit 3: Adding and Subtracting Mixed Numbers
Lesson 8 of 11

Objective: SWBAT solve problems involving the addition and subtraction of mixed numbers.

Big Idea: Regrouping fractions to whole numbers is not unlike regrouping ones to make a 10. Students use rich language as they learn the procedures for adding and subtracting mixed numbers.

  Print Lesson
5 teachers like this lesson
Math, modeling, Number Sense and Operations, Fractions, mixed numbers, add and subtract fractions, Critical Area
  55 minutes
screen shot 2014 04 22 at 11 09 10 am
Similar Lessons
6th Grade Math » Fraction Operations
Big Idea: What do students already know about fractions? What gaps do students have in their understanding? Students take the fractions pretest in order to inform instruction.
Somerville, MA
Environment: Urban
Andrea Palmer
Adding and Subtracting with Fractions
6th Grade Math » Number Sense
Big Idea: Using common denominators with fractions will help the students learn to divide fractions.
Plainfield, IL
Environment: Suburban
Michelle Schade
Recalling Prior Knowledge of Adding and Subtracting Fractions
5th Grade Math » Adding and Subtracting Fractions with Unlike Denominators
Big Idea: The denominator represents the WHOLE and the numerator represents the BITS/PIECES so in order to add fractions we need to have the same denominator.
Seattle, WA
Environment: Urban
James Ewing
Something went wrong. See details for more info
Nothing to upload