Addition and Subtraction Addition Relate addition to combining

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Addition and Subtraction

Addition and Subtraction

Addition Relate addition to combining two groups and counting on and record in a

Addition Relate addition to combining two groups and counting on and record in a number sentence using + and = signs. 13 + 24 = 37 Record addition by: model and images +

Your turn • 23 + 26 =

Your turn • 23 + 26 =

When the children are comfortable with this we move onto adding on a number

When the children are comfortable with this we move onto adding on a number line. 13 + 24 = 37 +10 13 23 +1 34 +1 35 +1 36 37

Your turn • 32 + 25 =

Your turn • 32 + 25 =

From this we move onto using partitioning both numbers. 35 + 23 30 +

From this we move onto using partitioning both numbers. 35 + 23 30 + 20 = 50 5+ 3=8 50 + 8 = 58

Your turn 43 + 56 =

Your turn 43 + 56 =

Develop methods for adding two digit and three digit numbers by partitioning second number

Develop methods for adding two digit and three digit numbers by partitioning second number only. 246 + 37= 246 + 30 = 276 + 7 = 282

Your turn • 145 + 54 =

Your turn • 145 + 54 =

Then we develop written methods for addition of two and three digit numbers using

Then we develop written methods for addition of two and three digit numbers using expanded methods of recording. 375 + 67 300 + 70 60 300 130 5 7 12 = 442

How can we apply this knowledge?

How can we apply this knowledge?

Problem solving T= Target I= Information N= Number sentence A=Answer

Problem solving T= Target I= Information N= Number sentence A=Answer

Mina and Ben play a game. Mina scores 70 points. Ben scores 42 points.

Mina and Ben play a game. Mina scores 70 points. Ben scores 42 points. How many points did they score in total? T= How many points did they score in total? I = 70 42 + N= 70 + 42 = A=

Your turn Mina and Ben play a game. Mina scores 35 points. Ben scores

Your turn Mina and Ben play a game. Mina scores 35 points. Ben scores 63 points. How many points did they score in total? T= I= N= A=

There are 265 children at Hill School. 102 children have a packed lunch. 27

There are 265 children at Hill School. 102 children have a packed lunch. 27 children go home for lunch. The other children have a school lunch. How many children have school lunch?

Subtraction Relate subtraction to taking away by counting back and as counting on and

Subtraction Relate subtraction to taking away by counting back and as counting on and record in a number sentence using the – and = signs.

Subtraction not crossing through the tens boundary. 46 – 25 = - 25 =

Subtraction not crossing through the tens boundary. 46 – 25 = - 25 = 21 In a subtraction calculation we always write the digits of the second number, we don’t draw the image!

Subtraction crossing the tens boundary. 53 – 27= - 27 = 26

Subtraction crossing the tens boundary. 53 – 27= - 27 = 26

Your turn Have a go, using models and images at these two calculations. 1.

Your turn Have a go, using models and images at these two calculations. 1. ) 57 - 32 = 2. ) 42 – 16 =

Once the children are comfortable with this strategy we move them onto subtraction on

Once the children are comfortable with this strategy we move them onto subtraction on a number line. 49 – 14 = -1 35 -1 36 -1 37 - 10 -1 38 39 49

Your turn 56 – 38 =

Your turn 56 – 38 =

Subtraction by partitioning not crossing the tens boundary. 48 – 32 = 40 –

Subtraction by partitioning not crossing the tens boundary. 48 – 32 = 40 – 30 = 10 8 - 2 = 6 10 + 6 = 16

Subtraction crossing the tens boundary using partitioning. 53 – 37 = 50 – 30

Subtraction crossing the tens boundary using partitioning. 53 – 37 = 50 – 30 = 20 10 3 - 7= We can’ t do this so we take one of the above tens. 13 – 7 = 6 10 + 6 = 16

Partitioning only the second number. 78 – 43 = 78 – 40= 38 38

Partitioning only the second number. 78 – 43 = 78 – 40= 38 38 - 3= 35

This is the same process even when crossing through the tens barrier. 63 -

This is the same process even when crossing through the tens barrier. 63 - 28 = 63 - 20 = 43 43 - 8= 35

Begin to record calculations in preparation for an efficient standard method- expanded decomposition. 81

Begin to record calculations in preparation for an efficient standard method- expanded decomposition. 81 - 57 70 and 11 50 and 7 20 and 4 = 24

Problem Solving Sita had 87 p. She spent 35 p. How much money did

Problem Solving Sita had 87 p. She spent 35 p. How much money did she have left? T= How much money did she have left? I = 87 p 35 p left - N= 87 p – 35 p= A=

There are 104 children at Delton School. 48 children are girls. How many are

There are 104 children at Delton School. 48 children are girls. How many are boys? T= How many are boys? I= 104 48 - N=104 - 48 A=