# Doubling and halving for an observed lesson.

Discussion in 'NQTs and new teachers' started by lillipad, Nov 14, 2009.

Ok here's my ideas so far, please read them and give me feedback (Good or bad -all is welcome!) Am not sure if i'm over complicating things.

Firstly to explain the concept we will look at socks! So i'll ask a child to the front and ask how many socks they've got on, and write it on the board. Then i'll ask the class to guess how many socks we will have if i invite another child to the front, then we'll try it and see and count. Then i'll say that two and two makes four and explain that two doubled = four. Then invite another two children up and tell them that this time we'll have double the number of children (Two lots of four socks!) What will be the answer? and then probably pause there.
Then i'll put up a coat hanger, and count on three pegs (With socks pegged on) and say that i need to double the number of socks - how many more pegs am i going to put on to the coat hanger to double it? and hope the answer will be three, then ask them to work with a thinking partner to double three to work out how many pegs altogether.
Am i over complicating? After that we'll go into independent work which i haven't thought of yet!

2. ### haj

For the independent activity, you could have an activity using numbercards upto 10( only even number ones) for LA pupils and upto 20 (only even numbers) for higher ability.

they could play game in small group where all number cards are in the middle of the table in a pile. there other small cars in middle which say double or half. Then eg. child A picks a number card from middle and turns it over eg. its 8, then turns the pile of double and half cards eg. get half .they have to work out what half of 8. they could have multilink to support them in middle of table and then eg. get 8 cubes and get 8 more count them up and total 16. then next childs turn. carry on till all the number cards have been used up. Obviously they could record them as number sentence eg. 8 + 8 = 16 when it is there turn in numeracy books, paper or whiteboards. all children in group could then check answer with child A whose turn it was.
if you wanted to you could obviously make it more competitiive by saying if they get it right get a counter etc. winner is person with most counters

sorry I can only think of that for now ( feel free to ignore it if feel its unsuitable)

also found these on cumbria grid for learning
<table cellspacing="0" cellpadding="0" class="MsoNormalTable" style="margin:auto auto auto 10.35pt;width:526pt;border-collapse:collapse;border:medium none;"><tr style="height:39.8pt;"><td style="padding-right:5.4pt;padding-left:5.4pt;padding-bottom:0cm;width:526pt;padding-top:0cm;height:39.8pt;background-color:transparent;border:windowtext 4.5pt solid;">Display a five-sided spinner with numbers 1-5. Activate the spinner. Pupils double the number generated.Have you tried&hellip;

3. ### haj

sorry about the page being over stretched and typos. send me a message if you want me to email you the link from cubria grid for learning they had some good ideas on there

Thanks Haj, that first idea is good for my middle abilities and my lower abilities who can just focus on doubling.
Not sure if i'm going to introduce halving or not, might do to the top abilities, but i think the lowers won't get doubling, let alone halving as well!

5. ### haj

Sorry wasn't sure whether you are doing more than one lesson on this doubling and halving, from my own experience I would say you may need at least a few lessons to cover this objective. You may well be best just concentrating on doubling for the observed lesson
with halving when I was doing this with my year 1's i explained that it was as though you wee sharing something two ie. halving it.So we used to have practical actvitites eg. for half of 6 we would count out 6 objects then use two small bowls and they give each bowl one each until all shared out and they then counted each bowl. They got their head round it after a good few lessons with lots of those kind of activities, although whether they would be able to remember this strategy to work out halves afterwards may be very unlikely, due to the children having very poor recall of strategies.

you could introduce the idea of having a double machine which keeps doubling everything,which might be good for the LA pupils. so eg. 1 child goes in and 2 come out etc. you could make a simple interactive whiteboard actvitiy along those lines and get children to discuss what will come out if eg. 6 spiders go in, then get them to discuss in pairs or talking partners how many would come out of this machine and get them to record as calculation/number sentence( which would help to stretch your more able--however this would have to be played by ear ie .may be too hard for them )

hope that helps