Singapore Math Level 2A & 2B – Challenge Questions of 2A - 11 Equivalent Questions
CHALLENGE QUESTIONS OF 2A
Solve the following questions. [Note: The following questions are presented as equivalent questions of Singapore Math Level 2A’s Challenge Questions, the only difference you will see in the Challenge questions is the different presentation style only, otherwise everything has the same meaning.]
1. Read the hints below and find the 3-digit number.
- The first digit is greater than 7 and is an smallest even number.
- The second digit is the smallest positive odd number and smaller than 7.
- The third digit is the difference between the first and the second digits.
Solution(1):
Numbers greater than 7 : 8, 9, 10,……..
smallest even number from 8, 9, 10,…….. = 8
So, 1st digit = 8
Positive odd numbers: 1,3,5,………
Smallest positive odd number: 1 and 1<7
So, 2nd digit = 1
1st digit - 2nd digit = 8 – 1 = 7
So, 3rd digit = 7
So, The 3-digit number is 817.
2. Ryan bought a skateboard for $126. He paid the shopkeeper the exact amount with 10 bills. Find the bills he used to pay.
Solution(2):
We can guess 10 bills as follows:
$126
= $100 + $20 + $6
= 2×$50 + 2×$10 + 6×$1
∵ He used two $50 bill, two $10 bill, six $1 bill.
3. Gina has twice as many oranges as Jessica. Jessica has 3 times as many oranges as Deepak. Deepak has 2 oranges. Draw a model, and find the number of oranges Gina has.
Solution(3):
Model of the story problem:
Deepak has 2 oranges;
Jessica has 2×3 = 6 oranges;
Gina has 6×2 = 12 oranges.
4. Carlos’s mass is 2 digits. The 1st digit is 3 times the 2nd digit. Carlos’s mass is greater than 35 kilogram and the two digits are odd numbers. What is Carlos’s mass?
Solution(4):
⓵ ⓶ ❸ ⓸ ⓹ ⓺ ⓻ ⓼ ❾
3 × 3 = 9
3 and 9 are odd numbers.
39 > 35
∵ Carlos’s mass is 39 Kg.
5. The sum of 2 facing pages of an diary can be divided by 3. The result of the division is 3. What are the 2 facing pages?
Solution(5):
9÷3=3
∵ The sum of 2 facing pages = 9
4 + 5 = 9
∵ The 2 facing pages are 4 & 5.
6. Schneider, Danny and Tyler each draw a giraffe. Schneider’s giraffe is longer than Danny’s giraffe but shorter than Tyler’s giraffe. Who has drawn the shortest giraffe?
Solution(6):
Model of the story problem:
Danny has drawn the shortest giraffe.
7. Simon had some chocolates. His mother gave him twice the number of chocolates Simon already had. His father gave him 3 times the number of chocolates his mother gave him. Simon had 27 chocolates in the end. How many chocolates did he have in the beginning?
Solution(7):
Model of the story problem:
27 ÷ 9 = 3
Simon had 3 chocolates in the beginning.
8. Jenny had a bill. She used it to buy a cloth for $20 and received the change in four bills of the same amount. What was the bill that Jenny had in the beginning?
Solution(8):
$100 – $20 = $80
$80 ÷ 4 = $20
Jenny would receive four $20 bills.
Jenny had one $100 bill in the beginning.
9. 3 numbers in a row or the sum of 3 consecutive numbers is 9. What are the 3 numbers?
Solution(9):
2+3+4=9
The 3 numbers are 2, 3, and 4.
10. The sum of 2 consecutive pages of an opened story book can be divided by 3. The result is 7. What are the 2 consecutive pages?
Solution(10):
3 × 7 = 21
The sum of the 2 consecutive pages is 21.
10 + 11 = 21
The 2 consecutive pages are 10 & 11.
11. Dante is heavier than Sierra but lighter than Mia. Who is the heaviest among the them?
Solution(11):
Model of the story problem:
Mia is the heaviest.
Also: