Solution Guide: Common errors in Ninja Excel exercises

1. Syntax and typing errors

The validation engine on the Ninja Excel platform is extremely accurate. Double-check these points in your formulas:

• Case sensitivity and spaces: While Excel functions aren’t case-sensitive, test strings inside lookup functions are. More importantly, ensure you haven’t added an extra space at the end of a word inside a cell or formula. It’s invisible to the eye, but it will break the validation.

• The beginning of a function: Although Excel technically allows using the plus sign (+) to start a formula, our platform only validates functions that begin with the equal sign (=).

• Argument separators: Make sure to always use semicolons (;) to separate elements within functions.

• Use of quotation marks: Any non-numeric text or criteria inside a function (e.g., "USA") must be enclosed in quotation marks.

• Parentheses in nested functions: When placing functions within one another, the number of opening parentheses must match the closing ones. A single missing parenthesis will invalidate the process.

2. Formats and mathematical logic

• Cell formatting: A common mistake is applying a format that looks right but isn’t what was requested. Check if you need to apply Currency ($) vs Percentage (%), or if a Number formatted cell should be Text. Remember: if a cell is formatted as Text, formulas won’t work.

• Hierarchy of Operations (PEMDAS): If your calculations don't match, remember the logical order: Parentheses, Exponents, Multiplication/Division, Addition/Subtraction. Use parentheses to make Excel calculate what you want first.

3. Workbook best practices

• The "active cell": If you’ve finished entering your formula but the cursor is still blinking inside the cell, the platform hasn’t registered the action yet. You must press Enter or Tab to exit the cell before clicking "Validate answers".

• Validate before continuing: If you press "Continue" without validating your exercises, the system won’t save that progress. You must hit "Validate answers" to confirm everything is correct to continue to the next class.

• Sheet cleanup: If you applied a filter or performed an action in a previous exercise, make sure to remove the filter or undo the action if the next task requires a “clean” sheet.

• Guideline vs. exercises spreadsheet: Double-check that you are working on the Exercises worksheet. The guideline worksheet is for visual reference only; you cannot edit it. Always return to your Exercise sheet to apply corrections and re-validate your work. To learn more about the platform's learning environment, check out our tutorial video, which you can find in the upper left corner of the platform, next to the Chatbox.

4. Special functions

• Off-catalogue functions: Some functions, such as DATEDIF, don’t appear in Excel’s suggestions drop-down menu but are fully functional. You must type these out manually from start to finish, including the parentheses.

5. Platform technical issues

If you are logged out unexpectedly or the workbook is lagging, check these technical factors:

• Inactivity: If the platform detects 15 minutes of inactivity, your session will time out. Any unsaved progress in your current lesson will be lost, and you’ll need to restart those exercises when re-entering.

• Cookies and cache: Make sure cookies are enabled in your browser. If you experience persistent lag, try clearing your browser cache with the shortcut Ctrl + Shift + R (Windows) or Cmd + Shift + R (Mac), or simply reload the page. If you are still having problems, read this article on how to optimize your browser.

• Internet connection: Lag can also be caused by a momentary drop in your connection speed. We recommend a connection of at least 100 Mbps. You can test your speed at https://fast.com/es/ or https://www.speedtest.net/.

Still having trouble? If your exercise still won't validate after checking these points, don't hesitate to reach out via our Chatbox.