Dusti Eide

TITLE:   
 Adding and Subtracting with Common Fractions (461-469 in math book)

CONTENT  AREAS:   
 Adding and Subtracting with Like Denominators (461-463)

GRADE  LEVEL:   
 4^th

MATERIALS   NEEDED:   
fraction kits, common fraction number line, paper, pencils 

KEY   CONCEPTS:   
 Adding and subtracting fractions with like denominators

 Basic mixed number conversion

EALR'S :   
 1.1 (show understanding of whole and fractional numbers, identify and compare whole numbers and simple fractions)

  5.3 (example of how math is used in everyday life – see examples from lesson)

GOALS (Remember the difference between goals and objectives):   
 Students will understand how to add and subtract simple mixed numbers and common fractions with like denominators

OBJECTIVES:   
 After solving some problems as a class, with the teacher, students will practice adding and subtracting common fraction with like denominators and demonstrate understanding by showing work on some problems they work out individually.

PROCEDURES:  (Label each step in the process:  Activating Prior Knowledge, Disequilibration, Elaboration, Crystallization)

• Introduction/Pre-assessment

  Activate prior knowledge:

Hand out fraction kits (pre-made)

Have common fraction number line on board

“If we have 4 equal pieces and we take two pieces away, what do we have left?  How can we show that using a fraction?”

“Now what do we have if we add one of those pieces back to the first two?  How can we show that in fraction form?

• Activity

Disequilibrium:

“Taking the problems above, how can we show this as a math problem?”

“If you do this activity for ¼ hour, take a break for ¼ an hour and then have lunch for ¾ an hour before you go home, how long will you be at school?” (use fraction kit or number line)

¼ + ¼ + ¾ =

“What do we see in this problem?”

Discuss how numerators get added and denominators stay the same.

Discuss how using the fraction kits you could change 6/4 into 1 2/4 or 1 ½.

“If you have ¾ of a pie and you eat ¼ of the pie, how much do you have left?”

¾ - ¼ =

Elaboration:

Practice these and show work using a number line or draw how you used your fraction kit in space provided (see attached worksheet)

• Closure

     List what we have learned about adding and subtracting like and different denominator fractions on board.  Ask students how they made mixed numbers from their fractions.
    
 

POST-ASSESSMENT   
   Have students complete a handout that has story problems with fractions and asks them to show their thinking by filling in blank shapes (boxes, circles, rectangles) to represent the problem and then solve. 

Teacher will then assess to see what concepts students understand and which they need to have more experience with.