1. Understand the Place Value:

* The decimal 3.78 has a "7" in the tenths place and an "8" in the hundredths place.

2. Write the Decimal as a Fraction:

* 3.78 can be written as 3 and 78/100.

3. Simplify the Fraction:

* Both 78 and 100 are divisible by 2.

* Simplify to 3 and 39/50.

Therefore, 3.78 is equivalent to the mixed number 3 39/50.