Sure, here are the corrections for the sentences that contain mistakes:

1. **Smartwatch is expensive and I cannot afford one.**
- Correction: **A smartwatch is expensive and I cannot afford one.**

2. **My Dad bought a new digital camera last year.**
- Correction: **My dad bought a new digital camera last year.** (Note: "Dad" should not be capitalized unless it is used as a proper noun, e.g., "I asked Dad.")

3. **I think that people won't need to do household chores any more in years to come because robot is being developed to help us do these tasks.**
- Correction: **I think that people won't need to do household chores anymore in years to come because robots are being developed to help us do these tasks.**

4. **I've got eyestrain because I've glued my eyes to my laptop screen all days.**
- Correction: **I've got eyestrain because I've glued my eyes to my laptop screen all day.**

5. **Golds are often used in computer chips nowadays.**
- Correction: **Gold is often used in computer chips nowadays.**

6. **I use my smartphone mainly for entertainments.**
- Correction: **I use my smartphone mainly for entertainment.**

7. **Time is precious and should not be wasted.**
- This sentence is correct.

8. **Keeping up with the lastest new is very important to my job.**
- Correction: **Keeping up with the latest news is very important to my job.**