Parents’ Maths Workshop Tuesday 3 rd December Aim: Understand how we teach subtraction Looking at how subtraction is taught at each level Explain and experience the strategies we use for written and mental calculations Suggested activities Please DO stops us and ask questions at any time

W HAT DOES S UBTRACTION LOOK LIKE IN E ARLY Y EARS AND KS1? What the government says ‘The principal focus of mathematics teaching in Key Stage 1 is to ensure that pupils develop confidence and mental fluency with whole numbers, counting and place value.’ How do we do this? Quick recall of number facts, for example, number bonds to 5, 10 and 20- relevant in addition and subtraction. Push vocab from an early age- less/ less than/ difference / minus/ subtract/ take away CPA

C ONCRETE … Using resources- cubes, counters, sweets, scarves… Having a number of resources out and then removing them. P ICTORIAL … Drawing pictures to support the calculation- crossing out. May/ may not need the concrete resources at this stage

A BSTRACT … Moving onto counting back in our heads We can support this by checking our answers using the previous 2 strategies NEED STRONG VOCAB U SING A N UMBER L INE … Starting on the largest number and “counting back” the smaller number For example- for 10- 3=

A ND NOW … Have a go at this problem using the strategies we have discussed. “Miss O’Prey bakes 20 cakes and Mrs Houlton eats 5 of them. How many cakes are left?” First- concrete stage (cubes) Second- Pictorial (pictures) Third- Abstract (number line/ in head)

W HAT DOES S UBTRACTION LOOK LIKE IN L OWER KS2? ‘The principal focus of mathematics teaching in lower Key Stage 2 is to ensure that pupils become increasingly fluent with whole numbers…This should ensure that pupils develop efficient written and mental methods and perform calculations accurately with increasingly large whole numbers.’ How do we do this?

B LANK N UMBERLINES Allows us to work with greater numbers Only uses the numbers we actually need Children must have a solid grasp of numbers before they begin Being able to subtract multiples of 10 and knowing number bonds supports this method

PARTITIONING (THE BEGINNING OF COLUMN SUBTRACTION) Splitting numbers into hundreds, tens and units to make them more manageable Supports mental strategies Ensures children have a thorough understanding of place value before moving on to column subtraction

P ARENTS ’ P ROBLEM … 179 snowflakes land on the windowsill, 36 of them melt immediately. How many are left? Can you use a blank numberline and partitioning to solve this problem?

W HAT DOES SUBTRACTION LOOK LIKE IN U PPER KS2? The principal focus of mathematics teaching in upper Key Stage 2 is to ensure that pupils extend their understanding of the number system and place value to include larger integers. At this stage, pupils should develop their ability to solve a wider range of problems…and problems demanding efficient written and mental methods of calculation… How do we do this? Column subtraction Confidence and ability to apply strategies learned lower in the school and apply them quickly and accurately to add larger numbers mentally and up to three two digit numbers.

A ND NOW … Column subtraction... How we were taught to do it?

Mental strategies The children apply confidently, efficiently and accurately strategies that they have learned throughout school. Mental strategies are reinforced, practised and refined so that the children can begin to manipulate numbers with confidence and they can complete mental maths subtractions under pressure and time constraints...

H OW CAN YOU SUPPORT AT HOME ? Baking/ cooking, shopping (finding change), eating sweets, books on the book shelf “ There are 15 books on the shelf, we choose 2 books. How many are left?” Watching TV programmes and pausing the TV to ask children to work out answers to subtraction or difference questions...such as ‘Bargain Hunt’...if the team bought the item at £40 and sold it at auction for £90 how much profit did the team make? Questioning… Next workshop- Multiplication- in the New Year

I T ’ S Q UESTION T IME !