Tag: calculating and mental strategies 3

Questions Related to calculating and mental strategies 3

$54.327\times 357.2\times 0.0057$ is the same as.

maths calculating and mental strategies 3 written methods dividing decimals division of decimals

  1. $5.4327\times 3.572\times 5.7$

  2. $5.4327\times 3.572\times 0.57$

  3. $54327\times 3572\times 0.0000057$

  4. $5432.7\times 3.572\times 0.000057$

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Correct Option: A
Explanation:
Given expression is $54.327\times 357.2\times 0.0057$
$\Rightarrow$  Number of decimal places in the given expression = $8$
$\Rightarrow$   Number of decimal places in (A) = 8
$\Rightarrow$   Number of decimal places in (B) = 9 
$\Rightarrow$   Number of decimal places in (C)= 7
$\therefore$    The expression in $(A)$ is the same as the given Expression.

Simplify $\left[\displaystyle\frac{(0.333)^3}{(0.111)^2}-\frac{(0.222)^4}{(0.111)^3}\right]$.

maths calculating and mental strategies 3 written methods dividing decimals division of decimals

  1. $1.331$

  2. $1.221$

  3. $1.484$

  4. $1.551$

Show answer
Correct Option: B
Explanation:
Given, $[\dfrac{(0.333)^3}{(0.111)^2} - \dfrac{(0.222)^4}{(0.111)^3}]$
We can solve like 
= $[\dfrac{0.333 \times 0.333 \times 0.333}{0.111 \times 0.111} - \dfrac{0.222 \times 0.222 \times 0.222 \times 0.222}{0.111 \times 0.111 \times 0.111}]$
= ${3 \times 3 \times 0.333} - 2 \times  2 \times 2 \times 0.222$
= $2.997 - 1.776$
= $1.221$

Divide $125.625$ by $0.5$

maths calculating and mental strategies 3 written methods dividing decimals division of decimals

  1. $251.25$

  2. $2512.5$

  3. $25125$

  4. $25.125$

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Correct Option: A
Explanation:

Division of $125.625$ by $0.5$ is

$\dfrac{125.625}{0.5}$ $=251.25$
Hence, the answer is $251.25$

Find the product:
$\displaystyle 0.05\times 0.09\times 5$

maths calculating and mental strategies 3 written methods dividing decimals division of decimals

  1. $0.025$

  2. $0.225$

  3. $0.005$

  4. $0.0225$

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Correct Option: D
Explanation:
Multiply the numbers without decimal point
i.e. $5\times 9\times 5=225$
$0.05$ have decimal point after $2$ digits
$0.09$ have decimal point after $2$ digits
So, the product will have decimal point after $2+2=4$ digits
Thus, the product of $0.05\times 0.09 \times 5=0.0225$

Solve the given expression:
$\displaystyle 9.826\div 10$

maths calculating and mental strategies 3 written methods dividing decimals division of decimals

  1. $98.26$

  2. $982.6$

  3. $0.09826$

  4. $0.9826$

Show answer
Correct Option: D
Explanation:
Denominator is one power of $410$
So, the number of digits after decimal point will increase by $1$ 
The division of $9.826$ by $10$ is 
$\therefore \dfrac{9.826}{10}$ $=0.9826$