Tag Archives: Celcius

Converting Fahrenheit to Celsius

To convert Fahrenheit to Celsius, we use the following formula,

                C = 5/9 (F – 32) = 10/18 (F – 32)

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The trick here is to recognize that 5/9 is the same as 10/18.  Hence after deducting 32, we add a zero (multiply by 10) to the result and successively dividing by 2 and 9 (MSC 11 – Dividing by 9) to effectively divide by 18.

  • Step 1.  Subtract 32
  • Step 2.  Multiply by 10
  • Step 3. Divide by 2
  • Step 4. Divide by 9

Let us solve look at some examples.

Example 1:          100 oF = 37.8 oC

  • Step 1.  Subtract 32:         100 – 32 = 68
  • Step 2.  Multiply by 10:    68 x 10 = 680
  • Step 3.  Divide by 2:         680 ÷ 2 = 340
  • Step 4.  Divide by 9:         340 ÷ 9 = 37 r. 7  =  37.7…  =  37.8

Example 2:           145oF = 62.8oC

  • Step 1.  Subtract 32:          145 – 32 = 113
  • Step 2.  Multiply by 10:      113 x 10 = 1130
  • Step 3.  Divide by 2:           1130 ÷ 2 = 565
  • Step 4.  Divide by 9:           565 ÷ 9 = 62 r. 7  =  62.7…  =  62.8

Easy and simple!