What Is a Rational Number? - mrscote

3.2 Adding Rational Numbers
FOCUS
• Solve problems
that require adding
rational numbers.
At 6 A.M., the temperature
was 3°C. By 10 A.M., the
temperature had risen
by 6°C. How can you use a
number line to determine
the temperature
at 10 A.M.?
Investigate 2
Use what you know about adding integers and adding fractions to determine each sum.
Draw a number line to illustrate each sum.
3 7
3 7
3 7
1 2
8 8
8 8
3 7
3 7
3 7
1 2
8 8
8 8
3 (7)
3
3
a 7 1 a2 7 8 8 b
8 8 b
3 (7)
3
3
a 7 1 a2 7 8 8 b
8 8 b
Reflect
Share &
Compare your strategies with those of another pair of students.
How did the first sum in each line help you determine the other sums?
How could you check your answers?
How are the strategies for adding rational numbers similar to those for
adding integers and adding fractions?
Check your ideas by adding other rational numbers.
106 UNIT 3: Rational Numbers