Developing visualisation of number
In my Reception class I wanted to develop the children’s ability to visualise amounts in their head and to be able to count them. I also wanted to develop their ability to subitize i.e. recognising familiar pattern arrangements such as those on a die or domino, and also to start counting in groups of numbers. This activity could also be used in Years 1 and 2.
How can I adapt this for older children? Could I build in estimation?
What I did
I made up a pack of about 20 A4 cards. Each card had an arrangement of pictures on it (see resource). The pictures are grouped into amounts and are generally arranged into the same patterns as seen on a dice or domino.
The children sit on the carpet and each child has a number fan. I then hold up a card and show it to them for a few seconds, not long enough for them to actually count the objects. They are then encouraged to visualise what they have seen (take a picture of it in your head). They then have to count how many objects there are by looking at the picture in their head, and show me the amount on their number fan. Once the children have all shown a number, we look at the card again and talk about ways that we could use to help work out the amount.
I wonder what the children said and what strategies they used. How can I encourage this?
This activity develops the children’s understanding of number in many ways. Firstly they learn to visualise a picture or pattern in their head and to process information from it. I began to see children’s eyes moving around as if they were counting imaginary objects and many used their fingers to stab at the air as they counted. Some children used their ability to subitize which led to simple addition e.g. Charlie recognised that there was a pattern of 5 and a pattern of 2 on a card without having to actually count each object and he could add them. They also learnt to conserve number, i.e. there are five and two more so count on 2 from 5.
I wonder if the children put the five in their heads and counted on. How could I build in time to discuss this with my class?
They also began to count in groups of numbers. For example, if there were three groups of 3 on a card, they began to count in threes and this was reinforced when we counted together to check. As we counted I emphasised the multiples of 3 in my voice – 1, 2, 3, 4, 5, 6, 7, 8, 9.