What Is a Rational Number? - mrscote

How Can I Learn from Others?
Three students discuss the answers
to these questions:
5 3
1. Evaluate: +
6 4
2. Evaluate: 3 - 5
5 3
1. Evaluate:
6 4
8
4
Dan said: The sum is , which simplifies to .
10
5
Jesse said: Dan must be wrong; the answer has to be greater than 1.
5 4
5
Philippe said: The answer has to be greater than , and is less than .
6 5
6
To help Dan, Jesse explained how he knew his answer was wrong:
5 3
1
I use benchmarks and estimate. Both and are greater than ,
6 4
2
1 1
so their sum has to be greater than 1.
2 2
Philippe explained his strategy for adding:
5 3
I know I can add the same types of fractions. For and
6 4
to be the same type, I write them as equivalent fractions
with the same denominator. Then I add the numerators.
5
6
10
12
3
4
9
12
5 3 10 9
Then,
6 4 12 12
10 9
12
19
,or 1 7
12 12
104 UNIT 3: Rational Numbers