UST Elementary Daily Math Challenge
Week 2 — Logical Reasoning
August 24–30, 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. If all red cards are even numbers and the card shows 22, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
2. If all red cards are even numbers and the card shows 24, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
3. If all red cards are even numbers and the card shows 26, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
4. If all red cards are even numbers and the card shows 28, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
5. If all red cards are even numbers and the card shows 30, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
Daily Practice
Questions 6–10
4
6. If all red cards are even numbers and the card shows 32, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
7. If all red cards are even numbers and the card shows 34, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
8. If all red cards are even numbers and the card shows 36, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
9. If all red cards are even numbers and the card shows 38, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
10. If all red cards are even numbers and the card shows 40, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
Daily Practice
Questions 11–15
5
11. If all red cards are even numbers and the card shows 42, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
12. If all red cards are even numbers and the card shows 44, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
13. If all red cards are even numbers and the card shows 46, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
14. If all red cards are even numbers and the card shows 48, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
15. If all red cards are even numbers and the card shows 50, which statement must be true? A) It is odd B) It is even C) It is less than 10 D) It is prime
Daily Practice
Questions 16–20
6
16. A number is greater than 21, less than 25, and even. One possible number is ___.
17. A number is greater than 22, less than 26, and even. One possible number is ___.
18. A number is greater than 23, less than 27, and even. One possible number is ___.
19. A number is greater than 24, less than 28, and even. One possible number is ___.
20. A number is greater than 25, less than 29, and even. One possible number is ___.
Daily Practice
Questions 21–25
7
21. A number is greater than 26, less than 30, and even. One possible number is ___.
22. A number is greater than 27, less than 31, and even. One possible number is ___.
23. A number is greater than 28, less than 32, and even. One possible number is ___.
24. A number is greater than 29, less than 33, and even. One possible number is ___.
25. A number is greater than 30, less than 34, and even. One possible number is ___.
Daily Practice
Questions 26–30
8
26. A number is greater than 31, less than 35, and even. One possible number is ___.
27. A number is greater than 32, less than 36, and even. One possible number is ___.
28. A number is greater than 33, less than 37, and even. One possible number is ___.
29. A number is greater than 34, less than 38, and even. One possible number is ___.
30. A number is greater than 35, less than 39, and even. One possible number is ___.
Daily Practice
Questions 31–35
9
31. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
32. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
33. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
34. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
35. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
Daily Practice
Questions 36–40
10
36. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
37. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
38. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
39. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
40. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
Daily Practice
Questions 41–45
11
41. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
42. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
43. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
44. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
45. Three students—Ava, Ben, and Cole—stand in a line. Ava is not first. Ben is before Cole. Give one possible order.
Weekly Challenge
Questions 46–50
12
46. Challenge: A secret number is between 76 and 86, divisible by 3, and odd. Find one possible number.
47. Challenge: A secret number is between 77 and 87, divisible by 3, and odd. Find one possible number.
48. Challenge: A secret number is between 78 and 88, divisible by 3, and odd. Find one possible number.
49. Challenge: A secret number is between 79 and 89, divisible by 3, and odd. Find one possible number.
50. Challenge: A secret number is between 80 and 90, divisible by 3, and odd. Find one possible number.
Answer Key — Questions 1–5
Answer + How to Solve
13
1. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
2. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
3. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
4. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
5. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
Answer Key — Questions 6–10
Answer + How to Solve
14
6. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
7. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
8. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
9. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
10. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
Answer Key — Questions 11–15
Answer + How to Solve
15
11. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
12. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
13. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
14. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
15. Answer: B
How to solve: The clue says every red card is even; the shown number is also divisible by 2.
Answer Key — Questions 16–20
Answer + How to Solve
16
16. Answer: 22
How to solve: List the whole numbers in the interval and choose the even one.
17. Answer: 24
How to solve: List the whole numbers in the interval and choose the even one.
18. Answer: 24
How to solve: List the whole numbers in the interval and choose the even one.
19. Answer: 26
How to solve: List the whole numbers in the interval and choose the even one.
20. Answer: 26
How to solve: List the whole numbers in the interval and choose the even one.
Answer Key — Questions 21–25
Answer + How to Solve
17
21. Answer: 28
How to solve: List the whole numbers in the interval and choose the even one.
22. Answer: 28
How to solve: List the whole numbers in the interval and choose the even one.
23. Answer: 30
How to solve: List the whole numbers in the interval and choose the even one.
24. Answer: 30
How to solve: List the whole numbers in the interval and choose the even one.
25. Answer: 32
How to solve: List the whole numbers in the interval and choose the even one.
Answer Key — Questions 26–30
Answer + How to Solve
18
26. Answer: 32
How to solve: List the whole numbers in the interval and choose the even one.
27. Answer: 34
How to solve: List the whole numbers in the interval and choose the even one.
28. Answer: 34
How to solve: List the whole numbers in the interval and choose the even one.
29. Answer: 36
How to solve: List the whole numbers in the interval and choose the even one.
30. Answer: 36
How to solve: List the whole numbers in the interval and choose the even one.
Answer Key — Questions 31–35
Answer + How to Solve
19
31. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
32. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
33. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
34. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
35. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
Answer Key — Questions 36–40
Answer + How to Solve
20
36. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
37. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
38. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
39. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
40. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
Answer Key — Questions 41–45
Answer + How to Solve
21
41. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
42. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
43. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
44. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
45. Answer: Ben, Ava, Cole
How to solve: Ben must be before Cole, and Ava cannot be first; this order satisfies both clues.
Answer Key — Questions 46–50
Answer + How to Solve
22
46. Answer: 81
How to solve: Check numbers in the range; keep only odd multiples of 3.
47. Answer: 81
How to solve: Check numbers in the range; keep only odd multiples of 3.
48. Answer: 81
How to solve: Check numbers in the range; keep only odd multiples of 3.
49. Answer: 81
How to solve: Check numbers in the range; keep only odd multiples of 3.
50. Answer: 81
How to solve: Check numbers in the range; keep only odd multiples of 3.
Week Complete!
Think • Reason • Solve • Explain