HOMEWORK: 1 – 27 odd
OBJECTIVES:
• Develop and explain algorithms for arithmetic with fractions ( rational
numbers ).
• Employ pictorial models to re present arithmetic with fractions (rational
numbers).
1. Adding & Subtracting Fractions (Rational Numbers) that have like
Denominators :
Addition:
Subtraction:
2. Adding Elementary Fractions That Have Unlike
Denominators
A. The National Assessment of Education Progress reports that 30% of 7th graders
in the US think that
B. Let’s discuss ways to help you convince your future
elementary and middle
school students that this is not true!!
 |
| Shade 1/2 of this fraction bar |
Shade 1/3 of this fraction bar |
The “problem” with this problem is that the two units have different
denominations. Thus, we must find a common denominator . Your students
should have already been introduced to the concept of LCM. Define the LCD as
the LCM (2, 3).
Show that the fractions 1/2 and 1/3 have equivalent fraction representations
with fraction bars divided into 6 pieces
Draw and shade a fraction bar to represent the sum .
C. The Addition of Rational Numbers That Have Unlike
Denominators:
To add rational numbers 
in which b > 0, d >
0, and b≠d:
1. Rename each fraction with the LCM(b, d)
2. Add the resulting fraction using the addition rule for like denominators
3. Subtracting Elementary Fractions That Have Unlike Denominators
Use fraction bars to solve 
4. Adding & Subtracting Mixed Numbers
A. Method 1 (Re grouping )
B. Method 2 (Improper Fractions)
