Number - addition and subtraction

By the end of year 2 the children should be able to:

• solve problems with addition and subtraction:
  • using concrete objects and pictorial representations, including those involving numbers, quantities and measures
  • applying their increasing knowledge of mental and written methods
• recall and use addition and subtraction facts to 20 fluently, and derive and use related facts up to 100
• add and subtract numbers using concrete objects, pictorial representations, and mentally, including:
  • a two-digit number and 1s
  • a two-digit number and 10s
  • 2 two-digit numbers
  • adding 3 one-digit numbers
• show that addition of 2 numbers can be done in any order (commutative) and subtraction of 1 number from another cannot
• recognise and use the inverse relationship between addition and subtraction and use this to check calculations and solve missing number problems

This year the children will extend their understanding of the language of addition and subtraction to include sum and difference.

Children practise addition and subtraction to 20 to become increasingly fluent in deriving facts such as using 3 + 7 = 10; 10 − 7 = 3 and 7 = 10 − 3 to calculate 30 + 70 = 100; 100 − 70 = 30 and 70 = 100 − 30. They will check their calculations, including by adding to check subtraction and adding numbers in a different order to check addition (for example, 5 + 2 + 1 = 1 + 5 + 2 = 1 + 2 + 5). This establishes commutativity and associativity of addition.

When ready the children may start to record addition and subtraction in columns which supports place value and prepares them for formal written methods with larger numbers in Year 3. 

Place Value

A good understanding of place value (the value of each digit in a number) is vital in primary-school maths. Here is how your child will be taught about units, tens, hundreds and thousands with number lines, arrow cards and more, as well as outlining how place value is used to help children visualise calculations.

 

What is place value?

Place value is the value of each digit in a number. It means understanding that 582 is made up of 500, 80 and 2, rather than 5, 8 and 2.

How are children taught to understand place value in KS1?

In school two maths aids are used to help make place value clear to children.

Deines blocks are blocks in which cubes represent units / ones, rods of ten cubes represent tens, flats  of 100 cubes represent hundreds and blocks of 1000 cubes represent thousands: 

In Key Stage 1, a child might be given some ten and units (ones) Deines blocks and asked to make a number such as 43. They would need to select 4 tens rods and 3 ones blocks. This makes it very clear to them that a two-digit number it made up of tens and ones. It also helps them to practise counting in tens.

Arrow cards look like this:

 

A child might be asked to make the number 34 using arrow cards. They would need to take the 30 and the 4 and put them together so that the arrows were lined up. This again helps to make clear that a two-digit number is made up of tens and ones.

It is absolutely vital that children understand place value before they can go onto adding and subtracting two-digit numbers.

Counting

In Year 2 we continue on from the learning from Year 1 and count forward and backwards in ones from any number within the range of 100.

 

Please practise daily counting with your children! Sometimes children have difficulties counting backwards and bridging the tens numbers (eg. 32,31,30,29 or 58 59 60 61 )

 

We then develop more fluency with our counting in different amounts such as in 2's,3's,5's and 10's which lead on to learning about the times tables and division facts of this numbers. 

 

We learn how to read and write our numbers in numerals and in the written form. 

 

We develop our reasoning skills and our problem solving skills throughout each lesson in order for us to help us understand more about the mathematical concepts we are learning about. 

 

We will learn about odd and even numbers and investigate the difference between them and the patterns that occur.