Question

Which is the smallest decimal number among the following.
 (A) $3.4$
(B) $4.4$
(C) $2.3$
(D) $2.1$

Answer 1

Hint: Generally, in these types of questions first we will compare all the numbers before decimal and choose the smallest from them. If two numbers are the same, then we will compare the first number after the decimal and if these are also the same then we will move ahead to compare in the same till we get the smallest number.

Complete step by step answer:
In the above question, we have to find the smallest number.
To find the smallest number first we will compare all the digits before decimal in the ascending order and then we will compare all the digits after decimal in the ascending order.
Therefore, $2 < 3 < 4$.
So, we know that our answer would be either option c or option d.
Now, we will compare the digits after decimal from option c and option d.
On comparing, we get
$1 < 3$.
Therefore, $2.1 < 2.3$ and the smallest number is $2.1$.
Hence, option (D) is correct.

Note:
We can also solve this question by arranging it first into descending order and then reversing the order. We know that numbers are said to be in descending order when they are arranged from the largest to the smallest number. After arranging the given numbers in descending order, we get $4.4,\,\,3.4,\,\,2.3,\,\,2.1$. Now, reversing the order, we get the ascending order $2.1,\,\,2.3,\,\,3.4,\,\,4.4$.
We can also represent all these decimal values on the number line and check which is smaller.

Here we can see $2.1$ is the leftmost point we have marked that will be the smallest number.