Today we are looking at halving!
Whenever there are doubles, there's always halves! We have looked at we can split/divide/cut objects in half and have stressed that by half it means in two pieces that are the same amount, that they are equal. As a warm up activity, and a useful tool to gauge how much your child knows about halving, you can have a go at cutting up an object/item in half with playdough, paper objects, shapes, and food wholes such as cake, pizza, sausage, and toast.
As the year progresses we then look to half numbers and link this to their knowledge of doubles. We only talk about halves of whole, even numbers at this stage in their learning journey. We hope for the children to explore and begin to make these links themselves through exploration.
Today you will need a set of ten objects - whatever is possible within your home. Again this can be counting blocks, Duplo pieces, Lego characters, buttons or whatever other exciting things you may have that will engage your child. You will also need two 'groups' whether that be with hula hoops, pieces of paper, large plates, masking tape on the floor etc.
Set them a superhero mission. They have to find five different ways to have the same amount in each group. They don't have to use all of them each time...they can have some left, but they need to make sure that they have the same in each group. But, the superhero HQ needs to know what they have found so it is important that they record each finding into the superhero HQ mission sheet...(you don't need to print this off, you can make your own if you are unable to print!)
Once they have completed their superhero mission sheet then ask them to have a look at what they have written. Is there anything or any patterns that they notice? Do these sums look familiar to them? Have they seen them somewhere else before?
Having spent the last two days working with doubles and these as number sentences it would be a great achievement if your child independently finds that these are all doubles sums! This is then the time to explain that halving is the opposite of doubles, as children go up through the school they will learn that this is known as in 'inverse operation'. Don't worry if your child needs help to identify these as doubles, but equally give them as many clues as possible without telling them the answer! In Reception we encourage children to make these links themselves as it is an essential part of learning and a valuable thinking skill.
Once the connection has been made spend time reading each double sum, but then also saying it as a half. For example, Double 1 is 2, Half of 2 is 1. Children will then begin to hear the pattern as well as see it. You can write this as you say it to reinforce and give the visual aid.
That's it! Your child has discovered that they can halve double numbers easily if they know their double numbers.
What to do next? Keep practising those double number facts and when your child is secure with these, continue practising with saying the halves too! Once your child understands how it works practically then they can move to learning these with mental recall. You can use songs, flashcards, practical applications such as playdough, drawing, painting like yesterday! If you are feeling particuarly brave then you could cut up your doubles symmetry artwork you've used the last couple of days and halve these!
Need a stepping stone?
Before you move on to finding halves, watch the Numberjacks video's below. The first looks at what half is. Spend some time making half practically as suggested at the start of the activity above.
The second Numberjacks video is about sharing fairly. This has a good link to finding halves as they need to understand first how to share fairly so that there is the same on both sides. Once you have had a practise at sharing fairly (with even numbers 2,4,6,8) then you can work together to complete the superhero mission above. Support your child to make links and don't worry if this takes longer than what feels natural to you as an adult - thinking time is twice as long as you'd feel it to be at this age. If they get stuck then guide them through encouraging their input as much as possible. Don't worry if your child doesn't make a link to doubles, just embed sharing fairly and that these are all even numbers. Once their doubles knowledge and understanding is secure then this can be revisited then.
Need a further challenge?
Your child may have picked up the link between doubles and halves quickly and is looking for that next challenge. If you have been working with doubles up to 20, then you can also do this with halving. Spend time on rehearsal and mental recall so that they are secure with these numbers. It takes a lot of time and practise so after this week keep revisiting it when you've got five minutes. Little and often can be the perfect balance! Good luck!