Step-Book With Professor Assessor ©

What’s It All About? You are going to learn: How to add and subtract large numbers using written methods ©

Recap on Place Value Remember – the position of a digit changes its value! Read these numbers: 10 units = 1 ten 10 tens = 1 hundred 10 hundreds = 1 thousand etc © Thousands HundredsTensUnitsHundredsTensUnits Our decimal number system is based on the number 10…

There are lots of ways to do this, but you MUST think about the place value of each digit and how they are connected: Example Split the numbers up: Add the parts: Written Addition © = 971

Traditional written addition does the same thing but is more compact and does not have as many steps: Example Line the numbers up – units with units etc: Add the parts: Written Addition ©  1 1

Example Written Addition ©  OR = 1977

© Your turn Try these: Check your answers with a calculator …

Again, there are different ways to do this, but you MUST think about the place value of each digit and how they are connected: Example 895  76 Split the numbers up: Subtract the parts: Written Subtraction © = 819 Why do we need to have 80 and 15 not 90 and 5…?

Again, traditional subtraction follows this idea BUT is more compact with less steps: Example 895  76 Line the numbers up – units with units etc: Subtract the parts: 1010 Written Subtraction © 

1010 Example 1396  Written Subtraction ©  OR =

©       103 Your turn Try these: Check your answers with a calculator …

The End © Sayonara…