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. While all other even numbers can be divided by 2, making them not prime, 2 can only be divided by 1 and 2, making it the only even prime number.

• Million: One million is equal to 1,000,000.
• Billion: One billion is equal to 1,000,000,000.

To find out how many millions are in a billion, we divide 1 billion by 1 million:

• 1,000,000,000 / 1,000,000 = 1000

Therefore, 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 will be rounded down to zero. In this case, 467 is less than 500, so it gets rounded down to zero.

To solve this, let's first find the sum of 178 and 69:
178 + 69 = 247
Now, we round 247 to the nearest hundred.
The nearest hundred to 247 is 200 because 247 is closer to 200 than to 300.
So, the sum of 178 and 69 rounded to the nearest hundred is 200.

1 million is equal to 1,000,000. Since 1 thousand is equal to 1,000, we can divide 1,000,000 by 1,000 to get:

1,000,000 ÷ 1,000 = 1000

So, 1 million is equal to 1000 thousands.

In the Indian number system, 1 crore is equal to 10,000,000. In the International system of numeration, 1 million is equal to 1,000,000. To convert crore into million, we divide 10,000,000 by 1,000,000:

10,000,000 ÷ 1,000,000 = 10

Thus, 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 given answer, 9875, is indeed the largest possible number that can be formed using these digits without repetition.

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

To find the difference between them:

10000 − 9999 = 1

So, the smallest 5-digit number exceeds the largest 4-digit number by 1.

The correct answer is d) 1.

To find the approximate length of Sita's ribbon, we need to subtract 1232 mm from Rita's ribbon length and then round the result to the nearest hundred.
Rita's ribbon length = 2070 mm Sita's ribbon length = Rita's ribbon length - 1232 mm
Sita's ribbon length ≈ 2070 mm - 1232 mm Sita's ribbon length ≈ 838 mm
When rounded to the nearest hundred, 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

Now, round this difference to the nearest tens. Since 178 is closer to 180 than to 170, the rounded difference is 180.

So, the correct answer is B: 170.

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 value of the product of 108 and 12, you can round the numbers to make the calculation easier:

• Round 108 to 110.
• Round 12 to 10.

Now, multiply:

110 × 10 = 1100

So, the estimated value is closest to 1000.

To round 28,549 to the nearest hundred, look at the tens place (which is 4). Since 4 is less than 5, we round down, keeping the hundreds place the same.

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

So, 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.

So, 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 need to first add 3537 and 3884, then round the result to the nearest tens.

1. Add the numbers:

   3537 + 3884=7421

2. 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 the problem has 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, and Priya has 210 Rs. 25 paise. To find out how much more Priya requires, 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

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

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

Thus, Priya needs 4070 paise more to buy the bag.

So, the correct answer is C: 4070 p.