Data Analyst Program

Excel · Week 1 of 4 · 4–5 hours

Excel Basics and Data Types

Get comfortable in the Excel window and understand the kinds of data a cell can hold.

Learning objectives

By the end of this week you will be able to:

  • Name the parts of the Excel window and move around a workbook.
  • Enter, edit and format data in cells.
  • Tell the difference between text, numbers, dates and logical values.
  • Spot and fix numbers or dates that Excel has stored as text.

Lessons

Excel Basics

An Excel file is called a workbook. Each workbook contains one or more worksheets (the tabs along the bottom). A worksheet is a grid: columns are labeled with letters (A, B, C) and rows with numbers (1, 2, 3). The box where a column and row meet is a cell, and every cell has an address, such as B3 (column B, row 3).

The key parts of the screen are:

  • The Ribbon: the menu across the top, grouped into tabs (Home, Insert, Formulas, Data).
  • The Name Box: top left, shows the address of the selected cell.
  • The Formula Bar: shows what is really inside a cell. If a cell displays 150 but holds =100+50, the formula bar shows the formula.

How analysts lay out data: put one header row at the top (for example Date, Region, Product, Units, Price), then one record per row below it. Avoid blank rows and merged cells inside your data, because many tools later in this course (sorting, filtering, PivotTables) expect a clean block.

Helpful shortcuts: Ctrl+Arrow jumps to the edge of your data, Ctrl+T turns a range into a formatted Table, Ctrl+Z undoes your last step.

Data Types

Every cell holds one kind of value. Knowing which kind matters because Excel only does math on numbers and dates.

  • Text (also called a string): words or codes such as North or SKU-104. By default text lines up on the left of the cell.
  • Numbers: quantities such as 42 or 19.99. Numbers line up on the right. Formatting (currency, percent, decimals) changes how a number looks, not its value.
  • Dates and times: Excel stores a date as a serial number (1 January 1900 is 1, so 1 January 2026 is 46023). That is why you can subtract one date from another to get the number of days between them.
  • Logical (Boolean): TRUE or FALSE. These come from comparisons such as =B2>100.
  • Errors: messages such as #DIV/0! (dividing by zero) or #N/A (a value was not found). They tell you something needs fixing.

The most common beginner problem: numbers stored as text. You will see them aligned left, often with a small green triangle in the corner, and SUM will ignore them. Fix them by selecting the cells, clicking the warning icon and choosing Convert to Number, or use =VALUE(A2). Dates typed in an unexpected style can be fixed with Data > Text to Columns.

Check yourself: the function =ISNUMBER(A2) returns TRUE if A2 really is a number.

Watch

Practice

Create a new workbook called Week1_Sales.xlsx. Type a header row (Date, Region, Product, Units, Unit Price) and enter 15 rows of made-up sales. On purpose, type three of the Units values with an apostrophe in front ('12) so they are stored as text. Then:

  1. Format Unit Price as currency and Date as a short date.
  2. Use =ISNUMBER() in a helper column to find the three text values.
  3. Convert them back to numbers and confirm the helper column now shows TRUE for every row.
  4. Press Ctrl+T to turn the range into a Table.

Check your understanding

Try each question first, then open it to see the answer.

What is the address of the cell in column D, row 7?

D7.

A column of numbers is lined up on the left and SUM returns 0. What is the likely cause?

The numbers are stored as text. Convert them with Convert to Number or the VALUE function.

Why can you subtract one date from another in Excel?

Because Excel stores dates as serial numbers, so subtracting gives the number of days between them.

Assignment

Submit your Week1_Sales.xlsx file plus two or three sentences explaining which data type each column holds and how you fixed the numbers stored as text.