# Limitation of real data type

**URL:** <https://forum.kx.com/t/limitation-of-real-data-type/11325>\
**Category:** Community Support\
**Tags:** kdb-and-q\
**Created:** [October 25, 2016, 11:51am UTC](https://forum.kx.com/t/limitation-of-real-data-type/11325 "2016-10-25T11:51:00Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![carfield11](https://avatars.discourse-cdn.com/v4/letter/c/ec9cab/32.png) [@carfield11](https://forum.kx.com/u/carfield11)\
**Post date:** [October 25, 2016, 11:51am UTC](https://forum.kx.com/t/limitation-of-real-data-type/11325/1 "2016-10-25T11:51:00Z")

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Hi all

When I loading a file from CSV to a table with real data type, I found that

a:“720.1”  
“E”$a

It will save 720.0999756 instead of 720.1, Just to confirm, it is because memory of real is not precise enough to hold 720.1 so I enter live with it or I need to switch the column to float, right?

Regards

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**Author:** ![effbiae](https://avatars.discourse-cdn.com/v4/letter/e/ecae2f/32.png) [@effbiae](https://forum.kx.com/u/effbiae)\
**Post date:** [October 25, 2016, 12:07pm UTC](https://forum.kx.com/t/limitation-of-real-data-type/11325/2 "2016-10-25T12:07:00Z")

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If you want to know the reason, see&nbsp;https://en.wikipedia.org/wiki/Floating\_point#Representable\_numbers.2C\_conversion\_and\_rounding

If you just want to see “720.1” without the gory details, see&nbsp;http://code.kx.com/wiki/Reference/DisplayPrecision

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<div class="post-metadata">

**Author:** ![carfield11](https://avatars.discourse-cdn.com/v4/letter/c/ec9cab/32.png) [@carfield11](https://forum.kx.com/u/carfield11)\
**Post date:** [October 27, 2016, 2:14am UTC](https://forum.kx.com/t/limitation-of-real-data-type/11325/3 "2016-10-27T02:14:00Z")

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Any suggested display precision for real datatype for view decimal properly for most case?&nbsp; .Q.fmt[8;4]?