Math Olympiad Worksheet for Class 4 - Number sense

Q1) In which of the following numbers does the digit 3 stand for 3 tenths?

1. 356.39

2. 763.87

3. 935.16

4. 975.93

Answer: C.

Explanation: In the number 935.16, the digit 3 is in the tenths place, representing 3 tenths.

Q2) Which of the following decimals is the greatest?

1. 0.043

2. 0.135

3. 0.410

4. 0.404

Answer: C.

Explanation: 0.410 is the greatest decimal among the given options.

Q3) 7 is a common factor of both ______ and _______.

1. 14, 17

2. 17, 21

3. 21, 27

4. 28, 35

Answer: D.

Explanation: Both 28 and 35 are divisible by 7.

Q4) In a 4-digit number, the sum of all the four digits is 17. The digits in the ones and thousands place are the same. The digit in the thousands place is twice the digit in the hundreds place. What is the number?

1. 1 091

2. 4 724

3. 6 326

4. 8 408

Answer: C.

Explanation: The number is 6326, as 6 + 3 + 2 + 6 = 17, and 6 is twice the digit in the hundreds place.

Q5) The digit 3 in 8.173 stands for 3 __________ .

1. tens

2. tenths

3. hundredths

4. thousandths

Answer: D.

Explanation: The digit 3 in 8.173 stands for 3 thousandths.

Q6) A 4-digit number is made up of digits from 0 to 9. Each digit can be used only once. What is the smallest possible odd number that can be created?

Answer: 1023

Explanation: The smallest odd number is formed by using the digits 0, 2, 1, and 3, resulting in 1023.

Q7) How many 4-digit numbers can be formed with the digits 4, 6, 3 and 9?

1. 4

2. 6

3. 12

4. 24

Answer: D.

Explanation: There are 4 digits, and each digit can be placed in any of the 4 positions, resulting in 4! = 24 different numbers.

Q8) Multiply 246 by 4 tenths.

1. 0.984

2. 9.84

3. 98.4

4. 984

Answer: C.

Explanation: Multiply 246 by 0.4 to get 98.4.

Q9) In 34 967, the value represented by the digit 3 is _____ times that of the value represented by the digit 6.

Answer: 500

Explanation: The digit 3 represents 300, and the digit 6 represents 6. Thus, 300 / 6 = 50 times.

Q10) What is the smallest possible whole number that can be rounded off to the nearest ten to get 13 400?

Ans: 13395

Explanation: The nearest ten for 13,400 is 13,400 itself, so the smallest whole number is 13,395.