Numbers and Data
Reading spreadsheet formulas
Read a spreadsheet formula, work out which cells it refers to, and say what number it will show.
A spreadsheet is a grid of cells, and every cell has a name made of its column letter and its row number: B3 is the cell where column B meets row 3. A cell can hold a number you typed, or it can hold a formula — an instruction that works something out. A formula always begins with an equals sign, which is how the spreadsheet knows you mean a calculation rather than a piece of writing.
A formula names cells, not numbers
This is the whole idea, and it is why a spreadsheet is worth having. A formula that says B3 does not mean the number that happened to be in B3 when you typed it — it means whatever is in B3 right now. Change B3 and every formula that mentions it works itself out again. A colon between two references, as in B2:B7, means a range: those two cells and everything between them.
Worked example
A sheet holds E1 = 15, E2 = 5 and E3 = 6. What does the formula =E1-E2 show, and what does =SUM(E1:E3) show?
Take =E1-E2 first. Read off what the two cells hold: E1 is 15 and E2 is 5.
Reading the values out before calculating stops you subtracting the row numbers by mistake.
Try it together
Now work through this one together. A sheet holds F1 = 7, F2 = 2 and F3 = 4.
Read each formula, swap the references for values, then work it out.
1.What number does =F1*F2 show?
Have a go
Have a go on your own. A sheet holds G1 = 6, G2 = 6 and G3 = 6. What number does the formula "=SUM(G1:G3)" show?
Ready to practise?
Eight questions on what you have just read. Nothing is timed, and you can play as many times as you like.