I noticed that some of your answers were wrong so I answered and corrected all of it. Hope my answer helps you.
15. 268
16. 94 R 114
17. 209
18. 246 R 211
19. 86 R 39
20. 908
21. 587
22. 1494 R 41
23. Emilio will have at least 67 full rows of trees. I know because if you divide the number of trees by the trees he planted per row, we'll get the total number of rows.
24. Camilla can make 96 necklaces.
Solution: (8,160 + 2,880) divided by (85 + 30) = 96.
25. 69 people received a free admission over the two days.
Solution: (6,742 + 5,487) divided by 175 = 69.
26. The divisors 2,000, 200, and 20 are all similar except the number of zeros. You can remove a zero from each dividend equal to the number of zeros in the divisor. The smaller the divisor, the greater the quotient when dividing the same number (80,000).
27. When a zero was added to the dividend, a zero was also added to 17.
Solution: 9,554 ÷ 562 = 17.
95,540 ÷ 562 = 170.
28. 111 moons could be lined up in a row between Earth and the Moon.
Solution: 384,400 ÷ 3476 = 110.587.
The number is 5 so I rounded it up.
If the number is 4 and below, I wouldn't round it up.
The solution for 15-19 is below. They're all in order.
15. 268
16. 94 R 114
17. 209
18. 246 R 211
19. 86 R 39
20. 908
21. 587
22. 1494 R 41
23. Emilio will have at least 67 full rows of trees. I know because if you divide the number of trees by the trees he planted per row, we'll get the total number of rows.
24. Camilla can make 96 necklaces.
Solution: (8,160 + 2,880) divided by (85 + 30) = 96.
25. 69 people received a free admission over the two days.
Solution: (6,742 + 5,487) divided by 175 = 69.
26. The divisors 2,000, 200, and 20 are all similar except the number of zeros. You can remove a zero from each dividend equal to the number of zeros in the divisor. The smaller the divisor, the greater the quotient when dividing the same number (80,000).
27. When a zero was added to the dividend, a zero was also added to 17.
Solution: 9,554 ÷ 562 = 17.
95,540 ÷ 562 = 170.
28. 111 moons could be lined up in a row between Earth and the Moon.
Solution: 384,400 ÷ 3476 = 110.587.
The number is 5 so I rounded it up.
If the number is 4 and below, I wouldn't round it up.
The solution for 15-19 is below. They're all in order.