Introduction

Students will again need access to the Activity Sheet in this lesson.

Some short written tasks should also be completed on the Student worksheet for this lesson. You can provide your students with paper copies or make a copy of the sheet yourself and share it with them as an assignment in Google Classroom, so they have their own editable digital copy.

 

Begin by recapping the key vocabulary learned in the previous lesson (cell, row, column, formulae).

Ensure the class can recall:

• How to label a cell with a cell reference
• How to group cells (in rows and columns)
• needing to enter ‘=’ at the beginning of a formula
• Where to find + (shift and =), x (*) and (/)

 

Using a formula

We can ask the spreadsheet to do far more complicated calculations.

Ask the children to think of a times table between 13 and 50, e.g. 23.

Do you know any of that times table?

 

2 x ?? = ?? it’s an easy double

10 x ?? = ?

What about 25 x ?? = 

 

Now use a spreadsheet to help.

In ‘Demonstration spreadsheet activities’ open the tab ‘tricky times tables’.

 

What do they notice?

What can they predict about cell A7, A11, A15?

Answers 7, 11, 15 these are the numbers that we are multiplying by

What can they predict about cell B5, B9, B19?

Answers 23, 23, 23 this it the number that is being multiplied

 

What can they predict about cell C1?

Expect = 1 * 23

 

However in this spreadsheet the cell references are being used to build the formula

Answer = A1*B1

 

 

Show the class how to build a formula using cell references.  [Slide 28]

 

On a blank spreadsheet page, or your own copy of ‘Demonstration spreadsheet activities’ > ‘tricky times tables’ tab, demonstrate how to use cell references.

Choose a new 'tricky' times table e.g 87.6

 

1. Enter ‘1’ into cell H1 and ‘2’ into cell H2

2. Highlight the cells H1 and H2 and using the small ‘handle’ at the bottom right-hand side drag down to cell H12

 

 

3. What do the children notice?  When might this be useful?  When might a [school administrator] use this?

4. Enter 87.6 into cell I1

5. Click in cell J1 and type =

6. Click in cell H1 followed by ‘*’

7. Click in cell I1 followed by the ‘enter’ key

8. The answer to 1 x 87.6 should appear in cell J1

9. Extend column I down to cell I12 using the handle

10. Repeat this with column J, all of the answers should calculate automatically.

 

This is demonstrated in this quick video guide, which is also available to the students via their activity sheet.

 

 

Main task

Ask the children to open the Activity sheet and the spreadsheet they created in week 1.

Ask the pupils to create their own tricky times table encouraging them to build the formula using cell references and to extend columns of data using the cell handles.

 

To finish

Working as a class can the children suggest How can we use a spreadsheet to work out the perimeter of these regular shapes?

• Triangle
• Square
• Pentagon
• Hexagon
• Heptagon
• Octagon
• Nonagon
• Decagon
• Hendecagon
• Dodecagon

 

They will need to remember that the perimeter is the distance all the way around the shape. 

They will need to know what a regular shape is.

Tell the class the length of each side (in all the shapes) is 6.7cm.

Encourage the class not to type 1 and 2 into the first 2 cells as they will only begin calculating the perimeter for an equilateral triangle.

Encourage the class to use the cell handles to quickly extend the data.

The formula should be = number of sides [cell ref] * 6.7