Count on and back within 1,000

Count on or back to find the missing number.

1. Chen asks: Count on: 151, 152, 153, □
2. Nia thinks: Count on: 100, 101, 102, □
3. Gus wonders: Count on: 250, 251, 252, □
4. Dara wonders: Count on: 163, 164, 165, □
5. Nia wonders: Count on: 379, 380, 381, □
6. Lia asks: Count on: 270, 271, 272, □
7. Ana wonders: Count on: 403, 404, 405, □
8. Mo asks: Count on: 326, 327, 328, □
9. Ana thinks: Count back: 855, 854, 853, □
10. Jon says: Count back: 271, 270, 269, □
11. Omar wonders: Count back: 526, 525, 524, □
12. Ana wonders: Count back: 924, 923, 922, □
13. Pia wonders: What number comes just before 924?
14. Jon asks: What number comes just before 318?
15. Pia asks: What number comes just before 397?
16. Kai asks: What number comes just before 904?
17. Pia says: What number is missing? 430, □, 432
18. Mo wonders: What number is missing? 751, □, 753
19. Fay thinks: What number is missing? 400, □, 402
20. Dara thinks: What number is missing? 125, □, 127