Multiplication

Why multiply?

Ever wondered why we multiply? How can we use our multiplication skills to help us better understand our world, to create, to solve? Here are a couple of fun multiplication projects/investigations to get you started. What investigation ideas would you like to see added? How else can we use our growing skills?

How to multiply

Have your ever wondered whether cultures all across the world multiply in the same way?
Have people throughout history always used the same approach?

In our multiplication studies this year, we're going to find out. We'll dive back in time to look at how they multiplied in Ancient Egypt, explore a centuries old medieval technique with an Italian name, and find out more about an approach referred to as the Russian peasant method. Intrigued? Let's begin. Which will be your favourite strategy?

Multiply like a Mummy (when they were alive)
Study this example of the Ancient Egyptian multiplication technique (written in modern Hindu-Arabic numerals) and see if you can deduce how it works. Can you crack the ancient thinking?

Try it for yourself.
Does the order of the multiplicand and multiplier matter?
Does it work every time?
Can you explain how it works?

Medieval Multiplication
Jump in your time machine and travel forward to around 1300AD.
Welcome to medieval times.

It was about this period that the first recorded instances of our next strategy were documented. Sometimes called Gelosian multiplication, it may have been named for its resemblance to the window lattices of Italy and Arabia. Can you see a similarity?

Take a closer look at the example above.

Can you see how each of the numbers in the lattice were calculated?

How has the final product, shown in red, been determined?

Can you see how and why it works?

How could we adjust this for numbers with more or fewer digits?

Give it a try using your own numbers.

Do you like it more or less than ancient Egyptian multiplication? Why?

Multipy by lines

Here's another interesting technique you may like to add to your repertoire.

Watch this video to learn how to multiply using lines. Yep ... lines.

More Multiplication Algorithms

Interested in doing a little extra practice? Click the pick above to choose from a range of printable revision sheets with answers.

The fundamental facts

So are you ready to practise? Click on the tool below and try to answer each question in the 5 seconds provided. If you can do that, you are well on your way to basic multiplication fact fluency!

Hint: Questions have been grouped in the fact families above. Use your doubling skills to help you.
Hint 2: Write down and practise the facts you haven't quite mastered yet - you may not need to practise all 21.

See the Pen Multiplication Fluency 2 by PakMatt (@PakMatt) on CodePen.

Prefer to test yourself with pencil and paper? Try this version, then use the document above to check your answers.

See the Pen Multiplication Fluency 1 by PakMatt (@PakMatt) on CodePen.

Ever had a song stuck in your head? Found yourself whistling along to an advertisement? Know all the words to a song you don't even like?
Annoying huh?
But is there a way we can use that ability our brain has for remembering things (annoying or otherwise) to our advantage?
Definitely. Some of us might even find this 'aural' approach to learning to be the most effective.
So, here for your listening pleasure (or not) are a couple of sing-along mulitiplication songs to help you with your square facts.
Think you can do better?
Prove it!
Come up with your own lyrics and tune and we'll record your song and put it on bamboolearners for others to enjoy?

When you've mastered your square numbers, it's often best to move to those 2, 4 and 8 tables listed in the doc above, then the 3, 6 and 9s.
By learning this way you may not need to learn your 7s as a sequence. You'd like to anyway? You legend!

A multiplication rap, rhyme or poem of our own

Starting to feel a little more inspired? Keen to create a rap, rhyme or poem of your own? Great idea!
The songs above are good, but we can definitely use what we've learned this year to improve them.
After all, now that we know our 2, 5 and 10 times tables, we know there are only 21 more facts to learn not 60.
We also know, from our study of memory, that strong and unusual imagery will really support our memorisation.
Start by using a rhyming dictionary to find words that rhyme with each of the products in the tables you want to learn.
Then select some interesting nouns or good descriptive words from the list that you can compose into a picture or story you think you will be able to easily remember.
Share your ideas with us here and we'll see if we can put together the ultimate multiplication rhyme.
Here's one to get your started.