To convert 85 mm to inches, follow these steps:

Step 1: Understand the conversion factor

There are 25.4 millimeters in 1 inch, so this is the conversion factor we will use to convert mm to inches.

Step 2: Set up the conversion equation

Since we are converting from mm to inches, we will set up our equation as:

85 mm × (1 inch ÷ 25.4 mm)

Step 3: Cancel out units

In the equation above, the unit of mm appears in both the numerator and denominator. This means we can cancel it out, leaving us with:

85 × (1 inch ÷ 25.4)

Step 4: Solve the equation

Now we can simply multiply 85 by 1 and divide the result by 25.4 to get our final answer in inches. This calculation can be done on a calculator or by hand.

85 × (1 inch ÷ 25.4) = 3.346456693

Therefore, 85 mm is equivalent to 3.346456693 inches.

Step 5: Round the answer

In most cases, it is acceptable to round the final answer to two decimal places. So, our final answer is:

3.35 inches

Therefore, 85 mm is equal to 3.35 inches.

In summary, to convert mm to inches, we simply multiply the value in mm by the conversion factor of 1 inch divided by 25.4 mm. Then, we can solve the equation and round the answer to two decimal places if necessary.