Which one is greater?
 $1$ meter $40$ centimeters$ + $ $60$ centimeters or \[2.6\]meters

Hint: We are provided with some values of measurement $1$ meter $40$ centimeters$ + $ $60$ centimeters and \[2.6\]meters and we have chosen which one is greater.
In this question, we are going to first convert the unit into one assumed unit and then we have added the resulting unit after adding the values we have to decide which value is greater than the other.
For unit conversion, the two things we must know are our starting unit and our desired units. In this question, our starting unit is a meter, and the desired unit is centimeters.
We will change all the meter values to centimeters.
Formula:
 for unit conversion, the key formula that will be used is given below
\[1m = 100cm\].

Complete step by step solution:
First, we are going to solve the first statement which is
$1$ meter $40$ centimeters$ + $ $60$ centimeters
Firstly, we will solve the first term as the second term is already in centimeters
$1$ meter $40$ centimeters,
We know that,
\[1m = 100cm\]
So, $1$ meter $40$ centimeters
\[ = 1 \times 100 + 40\]
\[ = 100 + 40\]
\[ = 140cm\]
Now,
\[140cm + 60cm\]
\[ = 200cm\]
Now we are going to convert the second term that is \[2.6\]meters
We know that
\[1m = 100cm\]
\[2.6m = 2.6 \times 100\]
\[ = 260cm\]
Now we are going to compare both values.
By seeing we can easily tell that
\[200cm < 260cm\]
So,
\[1m40cm + 60cm < 2.6m\].
Therefore, \[2.6\] meters are greater than $1$ meter $40$ centimeters $ + $ $60$ centimeters.

Note: Students must avoid calculation mistakes as they can lead them to incorrect and confusing answers.
To ace in unit conversion, one must remember the formulas of conversion. One should not round any quantities used within the calculation. Only round the final calculated quantity.
The best trick which will help the student is to do the conversion as a fraction \[1\] which is we have to write the conversion as a fraction that equals \[1\].