Bug? Zoho import create app from xls makes 'too long a decimal' from number

Bug? Zoho import create app from xls makes 'too long a decimal' from number

I did the following.

Made a new blank excel spreadsheet with the following data:

TestDec      Name
20.4            Bob

Saved the sheet.

When to create an application from file. Chose the spreadsheet in question.

The import fields are as follows:
"Single Line"      "Single Line"
"TestDec"           "Name"
"20.39999999999 "Bob"

No idea why zoho creates that decimal. If I change the fact it says "Single Line" to "Decimal", it still lists 20.399999999.

If I try to finish the import, it gives an error and says the Decimal has too many places.

Anyone know why on earth zoho creates this long decimal? Attached my .xlsx