Let's solve the problem step by step.
---
Understanding Rational and Irrational Numbers
-
Rational numbers can be expressed as a fraction $\frac{a}{b}$ where $a$ and $b$ are integers and $b \neq 0$. They include:
- Terminating decimals (e.g., 0.5)
- Repeating decimals (e.g., 0.333...)
- Integers
- Fractions
-
Irrational numbers cannot be written as a simple fraction. Their decimal form is non-repeating and non-terminating (e.g., $\sqrt{2}$, $\pi$).
---
Now, let’s go through each number:
---
Part 1: Classify and Convert
| Number | Rational or Irrational? | Convert dec./fraction |
|--------|--------------------------|------------------------|
| 1) 0.8 | Rational | $\frac{8}{10} = \frac{4}{5}$
✔ (already given) |
| 2) $\frac{-3}{10}$ |
Rational | Already a fraction: $\frac{-3}{10}$ |
| 3) $\sqrt{40}$ |
Irrational | $\sqrt{40} = \sqrt{4 \cdot 10} = 2\sqrt{10}$ → not a perfect square → irrational |
| 4) $\sqrt{81}$ |
Rational | $\sqrt{81} = 9 = \frac{9}{1}$ |
| 5) $2\frac{1}{3}$ |
Rational | $2 + \frac{1}{3} = \frac{7}{3}$ |
| 6) 0.35 |
Rational | $= \frac{35}{100} = \frac{7}{20}$ |
| 7) 0.3333... |
Rational | This is $0.\overline{3} = \frac{1}{3}$ |
| 8) $-9$ |
Rational | $= \frac{-9}{1}$ |
| 9) 3.4 |
Rational | $= \frac{34}{10} = \frac{17}{5}$ |
| 10) $\sqrt{2}$ |
Irrational | Cannot be written as a fraction; decimal is non-repeating, non-terminating |
---
Part 2: Directions – Classify and Tell Type
####
11) -0.6
- Is it rational or irrational?
- It is a terminating decimal.
- Can be written as $-\frac{6}{10} = -\frac{3}{5}$
- So,
rational
- Is it terminating or repeating?
- It
terminates after one decimal place.
✔ Answer:
- Rational
-
Terminating
---
####
12) $\sqrt{100}$
- $\sqrt{100} = 10$, which is an integer.
- Integers are rational.
- 10 can be written as $\frac{10}{1}$ → rational
- As a decimal: 10.0 → terminates
✔ Answer:
- Rational
-
Terminating
---
✔ Final Answers Table
| Number | Rational or Irrational? | Convert dec./fraction |
|--------|--------------------------|------------------------|
| 1) 0.8 | Rational | $\frac{4}{5}$ |
| 2) $\frac{-3}{10}$ | Rational | $\frac{-3}{10}$ |
| 3) $\sqrt{40}$ | Irrational | — |
| 4) $\sqrt{81}$ | Rational | $\frac{9}{1}$ |
| 5) $2\frac{1}{3}$ | Rational | $\frac{7}{3}$ |
| 6) 0.35 | Rational | $\frac{7}{20}$ |
| 7) 0.3333... | Rational | $\frac{1}{3}$ |
| 8) $-9$ | Rational | $\frac{-9}{1}$ |
| 9) 3.4 | Rational | $\frac{17}{5}$ |
| 10) $\sqrt{2}$ | Irrational | — |
---
Directions Part Answers
11) $-0.6$
→
Rational,
Terminating
12) $\sqrt{100}$
→
Rational,
Terminating
---
✔ Summary of Key Concepts Used:
- All fractions (including negative ones) are rational.
- Square roots of perfect squares are rational.
- Square roots of non-perfect squares are irrational.
- Terminating and repeating decimals are rational.
- Non-repeating, non-terminating decimals are irrational.
Let me know if you'd like this printed in a clean format!
Parent Tip: Review the logic above to help your child master the concept of classifying real numbers worksheet.