Multiplication Methods

Introduction

At primary school, you likely learnt how to multiply using either the grid method or the column method or the lattice method.  In today's lesson, we will look at some different ways to multiply numbers.  

You will first take a look at the following methods to see if you can understand them.

1. Grid Method: reading video

2. Lattice Method: reading video

3. Long Multiplication: reading video

4. Egyptian Method: reading video

5. Lines Method: reading video

If you are interested there are a few more here:

1. Gypsy Method: reading video

2. Russian Peasant Method: reading video

3. Multiplication Shortcuts: reading

For each of the methods, click on the respective reading and/or video.

Practice

Now, try out some of the methods to calculate the following questions.  You can use your calculator to check your results to see if you are correct:

1. 15 x 43

2. 37 x 21

3. 65 x 79

For something harder, try these:

1. 37 x 45

2. 61 x 29

3. 183 x 57

4. 248 x 619

Do you think you will be able to explain these to your peers?  Fill in this Google Form.

Presentation

In groups, you are now to design a 2-minute presentation that explains one of the Multiplication Methods to the rest of the class.

You can use this Script template to help you create your presentation.  You should make a copy and share it with all of your group members.

Your presentation should include:

• An explanation of how the method works including diagrams

• Examples using two-digit and/or three-digit numbers

• Each person in the group should speak during the presentation.

• You should use a script or speaker notes to write out what you are going to say (do not just put all of the words on the slides)

• You should use Canva to create the presentation (a template is available here - please make a copy).

• You should check over your calculations to make sure they are accurate.

• You should practice your presentation so that you know who is saying which part.

Things to consider:

• You can neatly write out diagrams on paper if you can not do it digitally.  You would then take a photo of your work and include that on one of the slides.

• You can refer back to the videos and documents in the last lesson to help you explain your method.

• Here is a video on how to create a video on Canva.

You will give your presentations to the rest of the class during your next lesson.

Further Practice 

Some essential skills introduced in this lesson are different methods of multiplication including column and grid methods.  You may also wish to practise division methods such as short division, long division and chunking.  Do the relevant skills practice on DrFrostMaths, CorbettMaths, MyiMaths and Eedi.  Watch any video and/or go through any online lesson as you see fit.

Transum

• Times Square - practise your times tables with this self-checking multiplication grid.

• Pairs 240 - find the pairs of numbers that multiply together to give a product of 240 in this collection of matching games.

• Three Ways - find three different ways of multiplying four different digits together to get the given target number. There are nine levels for this online challenge.

• Formal Written Methods - examples of formal written methods for addition, subtraction, multiplication and division.

• Number Skills Inventory - a checklist of basic numeracy techniques that every pupil should know.  Look especially at the adding and subtracting activities.

• Mix and Math - determine the nature of adding, subtracting and multiplying numbers with specific properties - not everything here is relevant.

• What Are They? - an online exercise about sums, products, differences, ratios, square and prime numbers - not everything here is relevant.

Negative numbers

• Boxed In Numbers - the classic dots and boxes game with the addition of some positive and negative numbers which determine your score.

• Negative Magic - four partially completed magic squares containing negative numbers. Fill in the missing numbers.

• Negative Numbers - use negative numbers in basic arithmetic and algebraic calculations and word problems.

• Reading Scales - a self marking exercise on the reading of scales of different types.

• Temperatures - test your understanding of negative numbers with this self marking quiz about temperatures.