Olympiad Test: Knowing Our Numbers - Class 6 MCQ

The only even prime number is 2. This is because:

• A prime number is defined as a number greater than 1 that has no positive divisors other than 1 and itself.
• All other even numbers can be divided by 2, which means they are not prime.
• In contrast, 2 can only be divided by 1 and 2, confirming it as the only even prime number.

• Million: One million equals 1,000,000.
• Billion: One billion equals 1,000,000,000.

To determine how many millions are in a billion, we divide:

• 1,000,000,000 ÷ 1,000,000 = 1000

Thus, 1 billion is equal to 1000 million.

The estimated value of 467 to the nearest thousand is zero because:

• When rounding to the nearest thousand, any number below 500 is rounded down.
• Since 467 is less than 500, it is rounded down to zero.

To solve this, we first find the sum of 178 and 69:

• 178 + 69 = 247

Next, we round 247 to the nearest hundred:

• The nearest hundred to 247 is 200 because 247 is closer to 200 than to 300.

Therefore, the sum of 178 and 69 rounded to the nearest hundred is 200.

1 million is equal to 1,000,000. To find out how many thousands are in a million, we can use the following steps:

• Recognise that 1 thousand equals 1,000.
• Divide 1,000,000 by 1,000:
• 1,000,000 ÷ 1,000 = 1000.

Therefore, 1 million is equal to 1000 thousands.

In the Indian number system, 1 crore is equal to 10,000,000. In the International system, 1 million is equal to 1,000,000. To convert crore to million, we perform the following calculation:

• Divide 10,000,000 by 1,000,000.
• This results in: 10,000,000 ÷ 1,000,000 = 10.

Therefore, 1 crore is equal to 10 million in the International system of numeration.

To find the smallest number among the given numbers, we simply compare their values:

• 1411
• 14504
• 2431
• 10001
• 9900

The smallest number is 1411, so the correct answer is D.

The question asks for the biggest 4-digit number that can be formed using the digits 5, 7, 8, and 9 without repetition.

The largest possible number formed with these digits is:

• 9875

This number is indeed the greatest that can be created using each digit exactly once.

The smallest 5-digit number is 10000, while the largest 4-digit number is 9999.

To determine the difference:

• 10000 - 9999 = 1

This shows that the smallest 5-digit number is greater than the largest 4-digit number by 1.

The correct answer is d) 1.

To find the approximate length of Sita's ribbon, follow these steps:

• Start with Rita's ribbon length: 2070 mm.
• Sita's ribbon is 1232 mm shorter than Rita's.
• Calculate Sita's ribbon length:
  • Sita's ribbon length = 2070 mm - 1232 mm
  • Sita's ribbon length ≈ 838 mm
• Round 838 mm to the nearest hundred:
• When rounded, Sita's ribbon length is approximately 800 mm.

First, calculate the difference in the number of tickets sold between the finals and the semi-finals:

10050 - 9872 = 178

Next, round this difference to the nearest tens:

• Since 178 is closer to 180 than to 170, the rounded difference is 180.

Thus, the correct answer is C: 180.

First, add the numbers:

267 + 132 = 399

Now, round 399 to the nearest ten. Since the last digit (9) is 5 or greater, we round up to the next ten:

399 rounded to the nearest ten is 400.

So, the correct answer is D: 400.

To estimate the product of 108 and 12, follow these steps:

• Round 108 to 110.
• Round 12 to 10.

Now, multiply the rounded numbers:

110 × 10 = 1100

Thus, the estimated value is closest to 1000.

To round 28,549 to the nearest hundred, follow these steps:

• Identify the tens place, which is 4.
• Since 4 is less than 5, we round down.
• This keeps the hundreds place the same.

Therefore, 28,549 rounded to the nearest hundred is 28,500.

The correct answer is B: 28,500.

In Roman numerals:

• 400 is represented as CD.
• C stands for 100, and D stands for 500.
• Since 400 is 500 minus 100, it is written as CD.

Thus, the correct answer is A: CD.

To find the smallest natural number that rounds off to 500 when rounded to the nearest hundred, consider the range of numbers that round to 500.

• Numbers from 450 to 549 round off to 500 when rounded to the nearest hundred.
• Therefore, the smallest number that rounds to 500 is 450.

So, the correct answer is C: 450.

We are given the equation:

15 × 1000 + 7 × _______ + 6 × 10 = 15760

Let's simplify the known values first:

• 15 × 1000 = 15000
• 6 × 10 = 60

Now, substitute these values into the equation:

15000 + 7 × _______ + 60 = 15760

Subtract 15000 and 60 from 15760:

15760 - 15000 - 60 = 700

So, the missing value is:

7 × _______ = 700

To find the missing value, divide 700 by 7:

700 ÷ 7 = 100

Thus, the missing value is 100.

So, the correct answer is C: 100.

To find the greatest natural number that rounds off to 500 when rounded to the nearest hundred, consider the range of numbers that round to 500.

• Numbers from 450 to 549 round off to 500 when rounded to the nearest hundred.
• The greatest number in this range is 549.

So, the correct answer is A: 549.

To solve this, we first need to add 3537 and 3884, and then round the result to the nearest tens.

• Add the numbers:

  3537 + 3884 = 7421

• Round 7421 to the nearest tens: The last digit is 1, so we round it down, resulting in 7420.

Now, let's compare the result with the given options: 1000, 7400, 7420, and 7440.

None of these options match exactly, but 7440 seems like a possible option if there is a small error in rounding or intended choices.

Thus, the closest matching option is 7420.

The price of the school bag is 250 Rs. 95 paise, while Priya has 210 Rs. 25 paise. To determine how much more money she needs, we first convert both amounts into paise.

• 250 Rs. 95 paise = 250 × 100 + 95 = 25,095 paise
• 210 Rs. 25 paise = 210 × 100 + 25 = 21,025 paise

Next, we subtract the amount Priya has from the total price of the bag:

25,095 paise - 21,025 paise = 4,070 paise

Therefore, Priya requires 4070 paise more to purchase the bag.