Sure! Let’s solve each problem step by step and determine whether the result is
Rational or
Irrational.
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🔢 Definitions to Remember:
-
Rational Number: A number that can be expressed as a fraction `a/b` where `a` and `b` are integers and `b ≠ 0`. This includes terminating decimals, repeating decimals, and integers.
-
Irrational Number: A number that
cannot be expressed as a simple fraction. Its decimal goes on forever without repeating. Examples: √2, π, √3, etc.
Also:
- The sum or product of two rational numbers is always
rational.
- The sum or product of a rational and an irrational number is usually
irrational (unless it cancels out, which is rare).
- The sum or product of two irrational numbers can be either rational or irrational — we must check case by case.
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##
✔ Problem-by-Problem Solutions:
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1. `1.10 + 0.01`
→ Both are
terminating decimals →
Rational
✔ Answer: Rational
---
2. `1.2 ÷ 0.5`
→ `1.2 / 0.5 = 12/5 = 2.4` → Terminating decimal →
Rational
✔ Answer: Rational
---
3. `1.15 + 0.07`
→ `1.22` → Terminating decimal →
Rational
✔ Answer: Rational
---
4. `1.17 ÷ 0.02`
→ `1.17 / 0.02 = 117 / 2 = 58.5` → Terminating decimal →
Rational
✔ Answer: Rational
---
5. `√7 + 8`
→ `√7` is
irrational (≈2.645...), 8 is rational.
→ Rational + Irrational =
Irrational
✔ Answer: Irrational
---
6. `√11 + 9`
→ `√11` is irrational, 9 is rational.
→ Rational + Irrational =
Irrational
✔ Answer: Irrational
---
7. `√17 × 5`
→ `√17` is irrational, 5 is rational.
→ Rational × Irrational =
Irrational
✔ Answer: Irrational
---
8. `√20 × 7`
→ `√20 = √(4×5) = 2√5` → Still irrational.
→ Multiply by 7: `7 × 2√5 = 14√5` → Still irrational.
✔ Answer: Irrational
---
9. `√225 × √825`
→ First, simplify:
- `√225 = 15` →
Rational
- `√825 = √(25×33) = 5√33` →
Irrational
→ So: `15 × 5√33 = 75√33` →
Irrational
✔ Answer: Irrational
> 💡 Note: Even though one part is rational, multiplying it by an irrational gives irrational.
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10. `√36 × √64`
→ `√36 = 6`, `√64 = 8` → both
rational
→ `6 × 8 = 48` →
Rational
✔ Answer: Rational
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## 📝 Final Answers:
1.
Rational
2.
Rational
3.
Rational
4.
Rational
5.
Irrational
6.
Irrational
7.
Irrational
8.
Irrational
9.
Irrational
10.
Rational
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Let me know if you’d like this turned into a filled-out worksheet PDF or need explanations for any specific step! 😊
Parent Tip: Review the logic above to help your child master the concept of rational and irrational numbers independent practice worksheet.