Step 1: Divide the whole number by the denominator of the fraction (in this case, 3).
In this case, 371 ÷ 3 = 123 remainder 2

Step 2: Write the whole number quotient as the whole number in the mixed number
123

Step 3: Write the remainder as the numerator of the fraction
2

Step 4: Write the denominator of the fraction as it is
3

Therefore, the mixed number is 123 2/3