# Coin Multiplication

Children recognise the coins that we use every day. Coin Multiplication teaches them to take a number (usually a 2d number) and then find the 1st, 2nd, 5th, 10th, 20th, 50th and 100th multiples of that number. If we include the £2 coin on our coin card, that means they find the 200th multiple as well. Our job is to show children how all of these multiples can be found simply by:

**multiplying by 10,****halving and****doubling.**

### Step 1

The first of the 5 steps for Coin Multiplication introduces us to a ‘1, 10 Card’ and shows us how to set it out. The 1^{st} multiple is the number itself and the 10^{th} multiple is the number itself, but this time made 10 times bigger.

### Step 2

The second step extends the ‘1, 10 card’ idea to produce a ‘1, 2, 5, 10 card’. Start with ‘easy’ numbers that lend themselves to getting the correct answers.

- Start as before by using the 1
^{st}multiple to find the 10^{th}multiple - Find the 2
^{nd}multiple by**doubling**the 1^{st}multiple - Find the 5
^{th}multiple by**halving**the 10^{th}multiple

Well done! This is a completed ‘1, 2, 5, 10’ Coin card. Keep practicing with a 1, 2, 5, 10 (spaces added) card until you can complete quickly (without having to use their fingers) delete before attempting the next step.

### Step 3

Now we extend the same ideas to write out a ‘Full Coin Card’. This includes using the 2^{nd} multiple to find the 20^{th}, using the 5^{th} multiple to find the 50^{th}. Then using the 1^{st} multiple to find the 100^{th}, and the 2^{nd} to find the 200^{th}. Once we have written out all these multiples (1^{st}, 2^{nd}, 5^{th}, 10^{th}, 20^{th}, 50^{th}, 100^{th} and 200^{th}) then we have a ‘Full Coin Card’! Congratulations! Now, practise with lots of different starting numbers (mainly using 2 digit whole numbers). The challenge is to be able to write a Full Coin Card like this for any 2 digit number in less than 60 seconds! Remember to always fill in the multiples in this order: 1^{st}, 10^{th}, 2^{nd}, 5^{th}, 20^{th}, 50^{th}, 100^{th}.

### Step 4

Once you can write out a ‘Full Coin Card’ fluently, try adding 2 of the coin multiples together. For example, you can find the 21^{st }multiple by adding the 20^{th} and 1^{st} multiples together, or find the 52^{nd} multiple by adding the 50^{th} and 2^{nd} multiples together. Try finding different variations of which multiples you can find, and combing this with different starting numbers.

### Step 5

At Step 5 we add 3 different coin multiples together. For example, you can find the 121^{st} multiple by adding the 100^{th}, 20^{th} and 1^{st} multiples together, or find the 252^{nd} multiple by adding the 200^{th}, 50^{th} and 2^{nd} multiples together.