Word Processing, Spreadsheets, Databases

What you need to know

• A word processor is application software for creating, editing, formatting, storing and printing text documents. Examples are Microsoft Word, LibreOffice Writer, WordPerfect, WordStar and Google Docs.
• The editing features are insert, delete, cut, copy, paste, undo and redo, and find and replace, which locates every occurrence of a word and substitutes another. The formatting features are font type, size, colour and style such as bold, italic and underline; alignment left, centre, right or justified; line spacing; indentation; bullets and numbering; columns; borders and shading.
• Page-level features are page setup with margins and paper size, orientation as portrait or landscape, header and footer, automatic page numbering, footnotes and endnotes, page break and print preview. Word wrap moves a word to the next line automatically when the current line is full, and WYSIWYG means that the screen shows the document exactly as it will print.
• Mail merge produces many personalised copies of one letter by combining a main document, which carries the fixed text and the merge fields, with a data source, which carries the list of names and addresses. A school uses it to print the same letter to five hundred parents with each parent's name inserted. This is a favourite examination question.
• A spreadsheet is application software that arranges numeric and text data in rows and columns and recalculates automatically when a value changes. Examples are Microsoft Excel, LibreOffice Calc, Lotus 1-2-3 and Google Sheets.
• The vocabulary is precise. A workbook is the whole file; a worksheet is one sheet within it; a column is identified by a letter and a row by a number; a cell is the intersection of a row and a column, and its cell address or reference is the column letter followed by the row number, such as B7. The active cell is the one currently selected, and a range is a block of cells written as A1:A10.
• Every formula begins with an equals sign. The operators are plus, minus, asterisk for multiplication, slash for division and the caret for exponentiation. A formula such as =B2*C2 multiplies the contents of two cells, and the answer updates automatically whenever either cell changes.
• The functions required are =SUM(B2:B10) to add a range, =AVERAGE(B2:B10) for the mean, =MAX and =MIN for the largest and smallest, =COUNT to count cells containing numbers and =COUNTA to count non-empty cells, =COUNTIF(B2:B10,">=50") to count only the cells meeting a condition, =IF(B2>=50,"PASS","FAIL") to test a condition and return one of two results, =VLOOKUP to fetch a value from a table using a key, and =ROUND, =RANK and =SUMIF for rounding, positions and conditional totals.
• Cell referencing decides what happens when a formula is copied. A relative reference such as B2 shifts as the formula is copied down or across. An absolute reference such as $B$2 stays fixed wherever it is copied, which is what you use for a single rate or constant. A mixed reference such as $B2 or B$2 locks only the column or only the row. Dragging the fill handle at the corner of a cell copies the formula down a column.
• Spreadsheets also produce charts, column, bar, line, pie and scatter, and support sorting, filtering and conditional formatting. In a school they are used for computing termly results, class averages and positions, for payroll, for fee records and for stock and budget tracking.
• A database is an organised collection of related data stored so that it can be retrieved, updated and managed efficiently. A database management system is the software that creates and controls it. Examples are Microsoft Access, MySQL, Oracle, Microsoft SQL Server, PostgreSQL and the older dBase and FoxPro.
• The data hierarchy runs bit, character, field, record, file or table, then database. A field is a single item of data such as Surname, and it forms a column. A record is the complete set of fields about one entity, such as everything stored about one student, and it forms a row. A table is a collection of records of the same type.
• A primary key is a field that uniquely identifies each record in a table and may not be duplicated or left empty, for example the admission number. A foreign key is a field in one table that refers to the primary key of another table, and it is what creates the relationship between tables, for example a ClassID in the Students table pointing to the Classes table. Relationships are one-to-one, one-to-many or many-to-many.
• The other objects are the query, which asks the database a question and returns only the records that match, written in SQL or built with query by example; the form, which gives a friendly screen layout for entering and viewing one record at a time; and the report, which arranges selected data for printing. A simple query reads: SELECT Surname, Score FROM Students WHERE Score >= 50 ORDER BY Score DESC. Using a DBMS instead of separate files reduces data redundancy, improves consistency and security, allows controlled sharing and makes backup and recovery systematic.