CASIO

Your calculator uses a recurring decimal when you input a value. Calculation results also can be displayed using recurring decimal form whenever applicable.

Inputting a Recurring Decimal

When inputting a recurrent decimal, press () before inputting its period (repetend) and then input the period up to the ending value. To input the recurring decimal 0.909090.... (0.90), perform the following operation: "0() 90".

Example 1: To input 0.33333… (0.3)

• 0
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• ()
• 

• 3
• 

Example 2: To input 1.428571428571... (1.428571)  (MthIO-MathO)

• 1()
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• 428571
• 

Example 3: To calculate 1.021 + 2.312

• 1() 021
  2() 312
• 

• Calculation result displayed as recurring decimal value:

  
• 

Displaying a Calculation Result as a Recurring Decimal Value

Calculation results that can be displayed as recurring decimal values will be displayed as such when ON is selected for the Rdec setting on the setup menu.
Pressing the key will cycle between the available calculation result formats.

Example 1: ¹₇ = 0.142857 = 0.1428571429 (Norm 1)  (MthIO-MathO)

• 17
• 

• Display as recurring decimal:

  
• 

• Decimal value according to Norm 1 setting:

  
• 

• Return to initial display format (fraction):

  
• 

Example 2: 1 ÷ 7 = ¹₇ = 0.142857 = 0.1428571429 (Norm 1)  (MthIO-MathO)

• 17
• 

• Display as fraction:

  
• 

• Display as recurring decimal:

  
• 

• Return to initial display format (Norm 1):

  
• 

Example 3: ¹₇ = 0.142857 = 0.1428571429 (Norm 1)  (LineIO)

• 17
• 

• Display as recurring decimal:

  
• 

• Decimal value according to Norm 1 setting:

  
• 

• Return to initial display format (fraction):

  
• 

Example 4: 1 ÷ 7 = 0.1428571429 (Norm 1) = ¹₇ = 0.142857  (LineIO)

• 17
• 

• Display as fraction:

  
• 

• Display as recurring decimal:

  
• 

• Return to initial display format (Norm 1):

  
• 

Conditions for Displaying a Calculation Result as a Recurring Decimal

If a calculation result satisfies the following conditions, pressing will display it as a recurring decimal value.

The total number of digits used in the mixed fraction (including integer, numerator, denominator, and separator symbol) must be no more than 10.

The data size of the value when displayed as a recurring decimal must be no larger than 99 bytes, calculated as: [number of digits (1 byte each)] + [1 byte for the decimal point] + [3 bytes for recurring decimal management code]. For example, the data size of 0.123 would be 4 bytes for digits, 1 byte for the decimal point, and 3 bytes for recurring decimal management code, for a total of 8 bytes.

Recurring Decimal Examples

Example 1: 0.3 + 0.45 = 0.78  (MthIO-MathO)

• 0() 3
  0() 45
• 

Example 2: 1.6 + 2.8 = 4.5  (MthIO-MathO)

• 1() 6
  2() 8
• 

Example 3: To confirm the following: 0.123 = ¹²³₉₉₉, 0.1234 = ¹²³⁴₉₉₉₉, 0.12345 = ¹²³⁴⁵₉₉₉₉₉  (MthIO-MathO)

• 123999
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• 
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• 12349999
• 

• 
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• 1234599999
• 

• 
•