Mathematics · Quantitative Aptitude

Number Operations and Properties

974 Questions

Improve your quantitative aptitude with these number operations and properties questions. The topics range from basic subtraction and division to highest common factor and roman numerals. Regular practice of these fundamentals builds speed for exams.

Basic arithmetic operationsHCF and number propertiesRoman numeral calculationsNumber series evaluation

Number Operations and Properties Questions

Multiple choice maths concepts of seven and eight digit numbers comparison of numbers comparing numbers operations on rational numbers indian place value chart largest and smallest numbers writing and expanding numbers

Which of the following options is arranged in descending order?

  1. $7,39,154$; $7,93,154$; $1,73,541$; $7,93,951$
  2. $8,50,76,745$; $8,50,76,547$; $8,50,67,574$; $8,50,67,547$
  3. $4,76,098$; $4,87,678$; $76,908$; $87,876$
  4. $3,15,45,001$; $3,51,54,100$; $4,15,45,001$; $5,25,45,010$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The correct descending orders are


1) $7,93,951 > 7,93,154 > 7,39,154 > 1,73,541$


2) $8,50,76,745 > 8,50,76,547 > 8,50,67,574 > 8,50,67,547$

3) $4,87,678 > 4,76,098 > 87,876 > 76,908$

4) $5,25,45,010 > 4,15,45,001 > 3,51,54,100 > 3,15,45,001$

Hence option B has the correct sequence of descending order.

Multiple choice maths concepts of seven and eight digit numbers comparison of numbers comparing numbers operations on rational numbers indian place value chart largest and smallest numbers writing and expanding numbers

Arrange in descending order:
$1,00,000; 99,999; 9,90,000; 1,10,000$

  1. $1,00,000; 99,999; 9,90,000; 1,10,000$
  2. $ 1,10,000; 9,90,000; 99,999; 1,00,000$
  3. $ 9,90,000; 99,999; 1,10,000; 1,00,000$
  4. $ 9,90,000; 1,10,000; 1,00,000; 99,999$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Comparing digits at lakh's place followed by ten thousand's, thousand's, hundred's, ten's and one's place,


We can arrange the given numbers in descending order as 
$9,90,000;\ 1,10,000;\ 1,00,000;\ 99,999$

Multiple choice maths be my multiple, i'll be your factor co-prime numbers lcm lowest common multiple (l.c.m.)

the first four common multiple of numbers $6,8,10$ are

  1. $10,20,30,40$
  2. $120,240,360,480$
  3. $8,40,80,120$
  4. $6,60,120,240$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
$6 = 2\times3$
$8 = 2^{3}$
$10 = 2\times5$

$\Rightarrow$ LCM of $6,8,10 = 2^{3}\times3\times5 = 120$

$\therefore 120$ is the least common multiple of $6,8,10$. Thus, all multiples of $120$ are common multiples of $6,8$ and $10$.

$\therefore$ First four common multiples $= 120,240,360,480$
Multiple choice maths be my multiple, i'll be your factor co-prime numbers lcm lowest common multiple (l.c.m.)

The 1st three common multiple of numbers $12,8,16 $ are

  1. $12,24,36$
  2. $8,16,24$
  3. $16,32,48$
  4. $48,96,144$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
$12 = 2^{2}\times3$
$8 = 2^{3}$
$16 = 2^{4}$

$\Rightarrow$ LCM of $12,8,16 = 2^{4}\times3 = 48$

$\therefore 48$ is the least common multiple of $12,8,16$. Thus, all multiples of $48$ are common multiples of $12,8$ and $16$.

$\therefore$ First three common multiples $= 48,96,144$
Multiple choice maths be my multiple, i'll be your factor co-prime numbers lcm lowest common multiple (l.c.m.)

Find first five common multiples of $1,2$ and $3$.

  1. $2,4,8,10,20$
  2. $3,6,12,30,60$
  3. $6,12,18,24,30$
  4. $1,2,3,4,5$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
$\Rightarrow$ LCM of $1,2,3 = 1\times2\times3 = 6$

$\therefore 6$ is the least common multiple of $1,2,3$. Thus, all multiples of $6$ are common multiples of $1,2$ and $3$.

$\therefore$ First five common multiples $= 6,12,18,24,30$
Multiple choice maths mental arithmetic estimation and rounding off estimations, bounds and rounding off rounding off numbers rounding of decimals

Round off to nearest lakhs: The given number is $38,65,62,048$

  1. $38,68,60,000$
  2. $38,65,600$
  3. $38,65,00,000$
  4. $38,66,00,000$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

To round of the given no in nearest lakh we need to see the value at ten thousand place which is $6$ it is more than $5$. 

So we round off lakhs digit to $5+1=6$
So we will round off. $38,65,62,048$ will become $38,66,00,000$

Multiple choice maths mental arithmetic estimation and rounding off estimations, bounds and rounding off rounding off numbers rounding of decimals

Round off  $231$ to nearest $100.$

  1. $200$
  2. $300$
  3. $250$
  4. $350$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\Rightarrow$  In number $231$,tens digit is $3$ 

$\Rightarrow$  Its tens digit is 3, which is less than 5. So, we replace each of the tens and ones digits by $0$ and keep the other digits as they are to round off the given number to nearest hundreds.
$\therefore$  Round of 231 to nearest 100 is $200$.

Multiple choice maths mental arithmetic estimation and rounding off estimations, bounds and rounding off rounding off numbers rounding of decimals

Round off $829$ to nearest $100$. 

  1. $800$
  2. $700$
  3. $900$
  4. $850$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\Rightarrow$  The given number is $829$

$\Rightarrow$  Its tens digit is $2$, which is less than $5$. 
$\Rightarrow$  So, we replace each of the tens and ones digits by $0$ and keep the other digits as they are to round off the given number to nearest $100.$
$\therefore$  Round off $829$ to nearest $100$ is $800$.

Multiple choice maths mental arithmetic estimation and rounding off estimations, bounds and rounding off rounding off numbers rounding of decimals

Round off the following number to the nearest $10$ and $100$:
$1634$

  1. $1630,1600$
  2. $1640,1730$
  3. $1740,1700$
  4. $1640,1734$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
$1634=163.4 \times  10^1$

Rounding to nearest 10, we round off $163.4$ to $163.0$ as $4$ is less than $5$

Answer: $1630$

Similarly for 100 th position 
$1634 = 16.34\times 20^2$

$16.34 = 16.30 = 16.00$

So the answer is $1600$.
Multiple choice maths mental arithmetic estimation and rounding off estimations, bounds and rounding off rounding off numbers rounding of decimals

Round-off $76,890$ to nearest $10$.

  1. $76,890$
  2. $76,880$
  3. $76,900$
  4. $77,000$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\Rightarrow$   The given number is $76,890$.

$\Rightarrow$   In number 76890, its unit digit is $0$, which is already nearest to 10.
$\Rightarrow$  So, don't need to change anything.
$\therefore$   $76,890$ is nearest to 10.