Exploring Long Addition

We take a lot for granted in our number system. Place value is one example. It’s difficult to see how revolutionary it is. It’s like the fish who doesn’t know what water is. We take…

Addition and Partitioning

The first stage of arithmetic is usually learning to put numbers together and take them apart. There are actually 2 main ways to put numbers together. We can do it with addition or multiplication. Here…

Counting On and Counting Back

Number sense is the ability to work with simple numbers in a more sophisticated way that allows you to do more complicated things. We saw last week that on average we are not able to…

Subitising

Subitising is the ability to see a number of objects. We can subitise up to 5 or 6 items that are not in a known order but not usually much more than that. This skill…