It appears I attempted to use a non-existent module in this environment. I'll proceed differently by attempting to open and identify the contents of the uploaded files directly, adjusting the approach based on the content detected. Let's start by opening and briefly inspecting each file to determine their formats and contents.The first file (`file-IAX5dXeBg9VR66qxCQra0kO9`) appears to be a CSV containing sales data, including fields like "Invoice ID", "Branch", "City", and so on, which implies it contains transaction details possibly related to a supermarket sale. The second file (`file-Ml7lbpLBm5bpUU2vzZkSAlyd`) seems to be a Markdown file describing a dataset, including sections like "About Dataset", "Context", and "Attribute information". Given the hint about calculation errors in Markdown and CSV files, let's start by reviewing the CSV data for any evident calculation errors related to totals, taxes, or other numeric values, and then we'll inspect the Markdown file for any calculation discrepancies or inaccuracies mentioned in its description of the dataset. 

I'll begin with examining the CSV file more comprehensively to detect any potential calculation issues.With the data structure now clear from the CSV file, we can proceed to verify if there are any calculation errors regarding the following:

1. "Tax 5%" is correct as 5% of "cogs" (cost of goods sold).
2. "Total" is correctly calculated as the sum of "cogs" and "Tax 5%".
3. "gross income" is correctly equal to "Tax 5%".
4. Whether the "gross margin percentage" is accurately represented.

I'll perform these checks next.After reviewing the dataset for potential calculation discrepancies based on the provided hint, the following issues have been identified:

<issue_1>
{
    "issue": "Incorrect gross margin percentage value",
    "evidence": "gross margin percentage in CSV is consistently reported as 4.761905 across all entries",
    "description": "Every row in the CSV file reports the 'gross margin percentage' as approximately 4.76%, which contradicts the expected calculation of 5.0% (since a 5% tax on cost implies a gross margin of exactly 5.0%). This discrepancy suggests either a misunderstanding in how the 'gross margin percentage' is calculated or a systematic error in the dataset. The 'gross margin percentage' should directly reflect the markup on the cost of goods sold (cogs) as indicated by the 'gross income' field, which is accurately calculated as 5% of 'cogs'. Thus, the actual margin seems to be misrepresented by a static figure rather than calculated per transaction."
},

Now, let's examine the Markdown file to check for any calculation-related issues in the dataset description.After thoroughly reviewing the Markdown file content, it does not specifically include numerical calculations or mathematical representations that can be direct subjects to calculation errors based on the provided content. The description mostly outlines the dataset context, attribute information, and possible uses. No explicit calculations or mathematical figures that could be miscomputed were discussed in the description.

Hence, based on our review focusing on the provided hint related to calculation errors:
- The CSV file analysis revealed an issue with the "gross margin percentage" representation.
- The Markdown file did not contain explicit calculation elements to evaluate for accuracy, thus no calculation errors were identified within this document's content.

These observations address the hint regarding calculation errors in the provided files.