Перевести число 139 из десятичной системы счисления в двоичную систему счисления. Сколько единиц содержит полученное число? Я не понимаю где единица а где ноль объясните)

Test 11. Present Simple, Present Continuous or Future Simple?

1. He (phone) you tomorrow when he (get) home from work.

2. ‘I (be) very busy now.’ ‘Why? What you (do)?’

3. Tom (not be) lazy. He (work) hard every day.

4. How often you (go) to the theatre?

5. We (go) to England for our holiday next year.

6. Wait for me! I (come) as soon as I (finish).

7. ‘You (work) hard today!’ ‘Yes, I have а lot to do.’

8. ‘What he usually (do) at weekends?’ ‘He usually (play) tennis.’

9. I (read) а very interesting book at the moment.

10. He is enjoying his holiday. He (have) а nice room in the hotel.

11. You (be) hungry? You (want) something to eat?

12. When I (come) home tomorrow, all my family (be) at home.

13. ‘Where is Ann?’ ‘She (have) а bath.’

14. You (see) that man over there? It’s our new teacher.

15. Look! Kate (dance) again. She (dance) every day.

16. How long it usually (take) you to get to school?

17. John (not go) for а walk today until his mother (come) back from work.

18. You (understand) me now?

19. ‘Would you like а cigarette?’ ‘No, thanks. I (not smoke).’

20. Let’s go out! It (not rain) any more.