Free Introduction to Numbers 02 Practice Test - 4th Grade
Question 1
Four friends play a number game. Each of them writes their favourite number. Who wrote the smallest number?
SOLUTION
Solution : D
To identify the smallest number from a given set of numbers having equal number of digits, we need to compare the digit in the thousands place of each number.
NumberNumber of thousands6–57267–29775–42551–2521
Since 7 > 6 > 5 > 1, the smallest number is the one with 1 in the thousands place which is 1252, written by Rahul.
Question 2
While writing a Roman numeral, only the numerals I, X, C and M can be repeated. V, L and D cannot be repeated.
SOLUTION
Solution : A
While writing a Roman Numeral, only the numerals I, X, C and M can be repeated. The numerals V, L and D cannot be repeated.
Question 3
20987 when rounded off to the nearest ten will be ___.
SOLUTION
Solution : B
To round off a number to the nearest ten, we check the last digit of the number.
If the last digit is less than 5, we round down the number to the nearest lower multiple of 10.
If the last digit is 5 or more than 5, we round up the number to the nearest higher multiple of 10.
In 20987, the digit in the ones place is 7. The nearest multiples of 10 for 20987 are 20980 or 20990.
Since 7 is greater than 5, 20987 will be rounded off to 20990.
Question 4
The sum of the largest 3-digit number and the smallest 4-digit number is _____.
SOLUTION
Solution : C
The largest 3-digit number is 999.
The smallest 4-digit number is 1000.Hence, their sum equals 999 +1000 = 1999.
Question 5
Which of the following statement is correct:
SOLUTION
Solution : C
We note that all 4 numbers have the same number of digits.
To find the smallest number from the given numbers, we need to check the digit in the tens place for each number since the digits in the thousands and hundreds place are the same for all of them.
NumberNumber of tens280–90289–99285–05289–09
Since 9 > 5 > 0, the smallest number is P = 2809.
To find the largest number (which is either 2899 or 2890), we need to check the digit in the ones place.
Since 9 > 0, the largest number is Q = 2899.
Question 6
Which of the following are true?
SOLUTION
Solution : A and B
In Roman numerals:
6 = VI
4 = IV
9 = IX
10 = X. Hence: 6 = VI and 4 = IV are correct
Question 7
Rohan’s house number has 2 in the thousands place. Which of the following cannot be his house?
SOLUTION
Solution : A
Only house number A begins with 5 in the thousands place. All other house numbers begin with 2 in the thousands place.
Hence A (5247) cannot be Rohan’s house number.
Question 8
There are ___ zeros in the smallest 5-digit number.
SOLUTION
Solution : A
The smallest 5-digit number is 10000. There are 4 zeros in 10000.
Question 9
The expanded form of 84926 is _____.
SOLUTION
Solution : B
84926 = 8 ten thousands +
4 thousands + 9 hundreds +
2 tens + 6 ones
= 80000 + 4000 + 900 + 20 + 6
Question 10
Choose the correct statement.
SOLUTION
Solution : A
52 =50 + 1 + 1 = L+ I + I = LII
102 = 100 + 1 + 1 = C + I + I = CII
140 = 100 + 40 = 100 + 50 - 10 = C + XL = CXL
42 = 40 + 1 + 1 = 50 - 10 + 1 + 1 = XL + I + I = XLII
Thus, the option "52 is written as LII in Roman numerals" is the only correct answer.