UST Elementary Daily Math Challenge
Week 10 — Math Detective Challenge
October 19–25, 2026
50 Problems • Grades 3–5 Focus
A little math every day. A little stronger every week.
Weekly Format
每天完成一小部分；周末完成 Challenge
2
Monday: Questions 1–10
Tuesday: Questions 11–20
Wednesday: Questions 21–30
Thursday: Questions 31–40
Friday / Weekend: Questions 41–50 + Challenge
Goal: Think first, calculate second, and explain your reasoning.
Daily Practice
Questions 1–5
3
1. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
2. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
3. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
4. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
5. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
Daily Practice
Questions 6–10
4
6. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
7. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
8. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
9. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
10. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
Daily Practice
Questions 11–15
5
11. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
12. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
13. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
14. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
15. Which strategy best fits: Find the next number in 5, 9, 13, 17, ___? A) Pattern B) Area C) Money D) Combination
Daily Practice
Questions 16–20
6
16. Mystery number: greater than 21, less than 26, and even. One possible answer is ___.
17. Mystery number: greater than 22, less than 27, and even. One possible answer is ___.
18. Mystery number: greater than 23, less than 28, and even. One possible answer is ___.
19. Mystery number: greater than 24, less than 29, and even. One possible answer is ___.
20. Mystery number: greater than 25, less than 30, and even. One possible answer is ___.
Daily Practice
Questions 21–25
7
21. Mystery number: greater than 26, less than 31, and even. One possible answer is ___.
22. Mystery number: greater than 27, less than 32, and even. One possible answer is ___.
23. Mystery number: greater than 28, less than 33, and even. One possible answer is ___.
24. Mystery number: greater than 29, less than 34, and even. One possible answer is ___.
25. Mystery number: greater than 30, less than 35, and even. One possible answer is ___.
Daily Practice
Questions 26–30
8
26. Mystery number: greater than 31, less than 36, and even. One possible answer is ___.
27. Mystery number: greater than 32, less than 37, and even. One possible answer is ___.
28. Mystery number: greater than 33, less than 38, and even. One possible answer is ___.
29. Mystery number: greater than 34, less than 39, and even. One possible answer is ___.
30. Mystery number: greater than 35, less than 40, and even. One possible answer is ___.
Daily Practice
Questions 31–35
9
31. A number plus 8 equals 21. Find the number.
32. A rectangle is 5 by 4. Find its area.
33. There are 5 tops and 3 bottoms. How many outfits?
34. A number plus 8 equals 24. Find the number.
35. A rectangle is 8 by 4. Find its area.
Daily Practice
Questions 36–40
10
36. There are 8 tops and 3 bottoms. How many outfits?
37. A number plus 8 equals 27. Find the number.
38. A rectangle is 11 by 4. Find its area.
39. There are 11 tops and 3 bottoms. How many outfits?
40. A number plus 8 equals 30. Find the number.
Daily Practice
Questions 41–45
11
41. A rectangle is 14 by 4. Find its area.
42. There are 14 tops and 3 bottoms. How many outfits?
43. A number plus 8 equals 33. Find the number.
44. A rectangle is 17 by 4. Find its area.
45. There are 17 tops and 3 bottoms. How many outfits?
Weekly Challenge
Questions 46–50
12
46. Final Challenge: What is the 5th square number?
47. Final Challenge: What is the 6th square number?
48. Final Challenge: What is the 7th square number?
49. Final Challenge: What is the 8th square number?
50. Final Challenge: What is the 9th square number?
Answer Key — Questions 1–5
Answer + How to Solve
13
1. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
2. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
3. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
4. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
5. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
Answer Key — Questions 6–10
Answer + How to Solve
14
6. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
7. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
8. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
9. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
10. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
Answer Key — Questions 11–15
Answer + How to Solve
15
11. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
12. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
13. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
14. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
15. Answer: A
How to solve: The numbers change by a repeated rule (+4), so use pattern recognition.
Answer Key — Questions 16–20
Answer + How to Solve
16
16. Answer: 22
How to solve: List candidates in the interval and apply the even-number clue.
17. Answer: 24
How to solve: List candidates in the interval and apply the even-number clue.
18. Answer: 24
How to solve: List candidates in the interval and apply the even-number clue.
19. Answer: 26
How to solve: List candidates in the interval and apply the even-number clue.
20. Answer: 26
How to solve: List candidates in the interval and apply the even-number clue.
Answer Key — Questions 21–25
Answer + How to Solve
17
21. Answer: 28
How to solve: List candidates in the interval and apply the even-number clue.
22. Answer: 28
How to solve: List candidates in the interval and apply the even-number clue.
23. Answer: 30
How to solve: List candidates in the interval and apply the even-number clue.
24. Answer: 30
How to solve: List candidates in the interval and apply the even-number clue.
25. Answer: 32
How to solve: List candidates in the interval and apply the even-number clue.
Answer Key — Questions 26–30
Answer + How to Solve
18
26. Answer: 32
How to solve: List candidates in the interval and apply the even-number clue.
27. Answer: 34
How to solve: List candidates in the interval and apply the even-number clue.
28. Answer: 34
How to solve: List candidates in the interval and apply the even-number clue.
29. Answer: 36
How to solve: List candidates in the interval and apply the even-number clue.
30. Answer: 36
How to solve: List candidates in the interval and apply the even-number clue.
Answer Key — Questions 31–35
Answer + How to Solve
19
31. Answer: 13
How to solve: Work backward by subtracting 8.
32. Answer: 20
How to solve: Area = length × width.
33. Answer: 15
How to solve: Multiply independent choices.
34. Answer: 16
How to solve: Work backward by subtracting 8.
35. Answer: 32
How to solve: Area = length × width.
Answer Key — Questions 36–40
Answer + How to Solve
20
36. Answer: 24
How to solve: Multiply independent choices.
37. Answer: 19
How to solve: Work backward by subtracting 8.
38. Answer: 44
How to solve: Area = length × width.
39. Answer: 33
How to solve: Multiply independent choices.
40. Answer: 22
How to solve: Work backward by subtracting 8.
Answer Key — Questions 41–45
Answer + How to Solve
21
41. Answer: 56
How to solve: Area = length × width.
42. Answer: 42
How to solve: Multiply independent choices.
43. Answer: 25
How to solve: Work backward by subtracting 8.
44. Answer: 68
How to solve: Area = length × width.
45. Answer: 51
How to solve: Multiply independent choices.
Answer Key — Questions 46–50
Answer + How to Solve
22
46. Answer: 25
How to solve: Square numbers are n×n, so 5×5=25.
47. Answer: 36
How to solve: Square numbers are n×n, so 6×6=36.
48. Answer: 49
How to solve: Square numbers are n×n, so 7×7=49.
49. Answer: 64
How to solve: Square numbers are n×n, so 8×8=64.
50. Answer: 81
How to solve: Square numbers are n×n, so 9×9=81.
Week Complete!
Think • Reason • Solve • Explain