# What's the difference?

# It's constant!

Post date: Feb 10, 2016 1:59:07 PM

Take a look at this quick presentation I've put together to explain **constant difference subtraction**:

Interested and want to find out more? Then check out some of these links:

**Dreambox tool**** **(go to 3rd grade addition and subtraction tools)

**My Addition & Subtraction Pinterest Board**

**More Number ideas/activities on PrimaryCPD**

You can also keep an eye out for constant difference subtraction in the

new, exciting scheme for maths "Operation Maths". Published by Edco, the are mini-lessons in the 4th to 6th class books, which explore **constant difference subtraction** and how the children can use it as a strategy, in both their written and mental calculations.