Tag: rounding decimals

Questions Related to rounding decimals

Divide $0.3297$ by $0.07$, correct to $2$ significant digits.

  1. $4.4$

  2. $4.7$

  3. $4.9$

  4. None of these


Correct Option: B
Explanation:

$0.3297 \div 0.07 = 4.71$

as the digit in ten's place is not greater than 5, it cannot be replaced.
$\therefore 0.3297 \div 0.07 = 4.7$

In the decimal, $2.4d7$, $d$ represents a digit from 0 to 9. If the value of the decimal rounded to the nearest tenth, is less than $2.5$, what are the possible values of $d$?

  1. $0,1,2$

  2. $0,1,2,3,4$

  3. $5,6,7$

  4. $5,6,7,8,9$


Correct Option: B
Explanation:

The correct answer is ${0,1,2,3,4}$.

: If $d \ge 5$, the decimal rounded to the nearest tenth will be greater than $2.5$.
Hence, option B is correct.

$\displaystyle 6.743\times 100$ is equal to _____ 

  1. $674.300$

  2. $.674300$

  3. $67.4300$

  4. $6.74300$


Correct Option: A
Explanation:

The number of decimal places from the right of the number in the question will be in the product at the same number of places.

$6.743×100=674.300$   ($3$ decimal places)
So option A is the correct answer.

Calculate the value of the following expression by appropriate rounding off of the numbers:
$\displaystyle 0.43\times 0.87=$

  1. $0.31$

  2. $0.35$

  3. $0.36$

  4. $0.38$


Correct Option: C
Explanation:
Since in the case of $0.43$, the last digit is less than $5$, it would be rounded off to $0.4$
Likewise, since the last digit of $0.87$ is greater than $5$, it would be rounded off to $0.9$
$0.43 \times 0.87$ thus becomes $0.4 \times 0.9 = 0.36$

On rounding off the decimal part of $32.4$ to the nearest one, we get

  1. $30$

  2. $32$

  3. $33$

  4. $35$


Correct Option: B
Explanation:

In $32.4$, digit $4$ is less than $5$ so we will round off to $32.$
After rounding of $32.4$ will become $32.$

While rounding off, if the digit to be dropped is less than $5$, then the preceding digit:

  1. increases by $1$

  2. remains unchanged

  3. decreases by $1$

  4. None of the above


Correct Option: B
Explanation:
When rounding, you examine the digit following (i.e., to the right of) the digit that is to be the last digit in the rounded off number. The digit you are examining is the first digit to be dropped.

  1. If that first digit to be dropped is less than $5$ (that is, $1, 2, 3 $ or $4$), drop it, and also drop all the digits to the right of it.
  2. If that first digit to be dropped is more than $5$ (that is, $6, 7, 8$ or $9$), increase by 1 the number to be rounded, that is, the preceeding digit (to the digit being dropped).
Thus, in our case, since the digit to be dropped is less than $5$, we make no change to the preceding digit. 

Sohan wishes to order salt for himself, but the salt is only sold in $30$-pound bags. He currently has $75$ pounds of salt, and he needs to have a minimum of $200$ pounds. Determine the inequality which shows the possible values for the number of bags, b, that Macro needs to order in order to meet his minimum requirement.

  1. $\displaystyle b\ge 4$

  2. $\displaystyle b\ge 5$

  3. $\displaystyle b\ge 6$

  4. $\displaystyle b\ge 7$


Correct Option: B
Explanation:

Sohan needs to have $200$ pounds but he currently has $75$ pounds

And bags sold only $30$ pounds bag.
Then sohan take bags in $75$ pounds $=$ $\dfrac{75}{30}=2.5$ says 2
But he needed bages in $200$ pounds $=$ $\dfrac{200}{30}=6.67$ says 7
Then the inequality of number of bags (b) $=6.67-2.5=4.16$ says $5$
Hence, option B is correct.

66.7 can be approximated to

  1. 67

  2. 92

  3. 88

  4. 127


Correct Option: A
Explanation:

Given 66.7

As we can see number after decimal is more than 5 so approximated value is 67

Choose the correct alternative.
If $\bar {d}=-20.83,\bar {x}=254.17$, then $A=?$

  1. $270$

  2. $275$

  3. $233.34$

  4. $12.20$


Correct Option: A