What Is a Rational Number? - mrscote

Discuss
the
ideas
1. What does a fraction bar indicate?
2. As the number of operations increases and the expressions become
more complex, it is easy to make mistakes.
What can you do to prevent yourself making mistakes?
Practice
Check
3. Evaluate. Do not use a calculator.
a) 2.3 (1.6) (0.8)
b) (14.8) 0.9 3.1
c) (12.8) (0.2) 4.5 0.5
d) (4.8) (0.4 0.6) 2
4. Evaluate. Do not use a calculator.
1
1
a) a 3
2 4 b 3
b) a5 a1 a 1 4 3 4 3 4 b 2 b 2 b
1
c) a 7 a2 a 1
10 b 5 b 4 b 2
5
d) a 2
3 8 2
6
5
3 b 12
Apply
5. a) Use a calculator to evaluate the
expression below. Key in the expression
as it is written.
2.8 1.4 4.5
b) Does the calculator follow the order of
operations or does it perform operations
from left to right? How did you find out?
6. Estimate which expression has the greatest
value. Then use a calculator to evaluate each
expression to verify your prediction.
a) 9.1 3.5 (4.2) 2 b) (9.1 3.5) (4.2) 2
c) 9.1(3.54.2) 2 d) 9.1[(3.5)(4.2) 2 ]
7. Evaluate.
1 1 1 1
a) a 2
3 b 4 2 2 3
b) a2 1
c 1
3 b 4 a1 2 bd 3
1
c) a2 c 1
3 b 4 a1 2 bd 3
d) a2 c 1 4 a1 2 b 1 3 b 3 d
8. Find the errors in each solution.
Write the correct solution.
a)
b)
(–3.7) x (–2.8 + 1.5) – 4.8 ÷ (–1.2)
= (–3.7) x (1.3) – 4.8 ÷ (–1.2)
= –4.81 – 4.8 ÷ (–1.2)
= –9.61 –
÷ (–1.2)
= 8.0083
–
3
–
4
x
3
8
÷ – 4
5 10 5
= –
15
40
–
32 3
x ÷ –
40 10
= – 47 4
40
x 3
10
÷ – 5
= –
141 4
400 ÷ – 5
= – 141 5
400
x – 4
=
(–141) x (–5)
400 x 4
=
705
1600
4
5
140 UNIT 3: Rational Numbers