Answer:
(a)
Given expression: 49% of 162
we can write 49% as [tex]\frac{49}{100}[/tex]
then;
[tex]\frac{49}{100} \times 162 = \frac{49 \times 162}{100} = \frac{7938}{100}=79.38[/tex]
Therefore, the estimate of the given expression is, 79.38.
(b)
Using mental math to calculate 49% of 162.
Mental math is used as a way to calculate an estimate quickly.
We can write 49% = 50% -1%
(50%-1%) of 162 = 50% of 162 -1% of 162
so,
50% of 162 = [tex]\frac{50}{100} \times 162 = \frac{1}{2} \times 162 = 81[/tex]
and
1% of 162 = [tex]\frac{1}{100} \times 162 = \frac{162}{100} = 1.62[/tex]
Now, subtract these we get;
81 - 1.62 = 79.38
Therefore, by using mental math 49% of 162 is, 79.38
