YEAR 2 ADDITION AND SUBTRACTION Session 6 Subtracting

YEAR 2– ADDITION AND SUBTRACTION Session 6 – Subtracting 2 digit numbers with exchanging.

In Year 2, we use visual maths to solve two digit - two digit questions. Before we start. . Let’s remind ourselves…. A two digit number has tens and ones. 20 2 tens 0 ones 20 0

Let’s start by taking a one digit number away from a two digit number using visual maths. 32 – 7 = 25 To start, we draw the first number (the largest number) in our sum. 32 has 3 tens and 2 ones. Tens Ones Then we look to cross out the second number. This number is too big! We don’t have 7 ones to cross out. We need to break down a ten stick into ten ones. We cross out 1 ten and draw ten ones instead. Now we can cross out the 7 ones the question’s asked us to. Now, we count up what we have left. We must start with the ones. Then the tens. 2 5 We’ve got 2 tens and 5 ones. 2 tens = 20 + 5= 25.

Your turn…. . Try this questions and then check your answer with my steps afterwards. 24 – 8 = 16 To start, we draw the first number (the largest number) in our sum. 24 has 2 tens and 4 ones. Tens Ones Then we look to cross out the second number. This number is too big! We don’t have 8 ones to cross out. We need to break down a ten stick into ten ones. We cross out 1 ten and draw ten ones instead. Now we can cross out the 8 ones the question’s asked us to. Now, we count up what we have left. We must start with the ones. Then the tens. 1 6 We’ve got 1 tens and 6 ones. 1 tens = 10 + 6= 16.

Now let’s move on to taking a two digit number away from a two digit number using visual maths. 43 – 29 = 16 To start, we draw the first number (the largest number) in our sum. 43 has 4 tens and 3 ones. Then we look to cross out the second number. This time we have 2 tens and 9 ones to take away. Let’s start with the ones. We do not have 9 ones to take away. Tens Ones We need to break down a ten stick into ten ones. We cross out 1 ten and draw ten ones instead. Now we can cross out the 9 ones the question’s asked us to. We mustn’t forget to take away then tens in the question. I need to take away 2 more tens. Now, we count up what we have left. We must start with the ones. Then the tens. 1 4 We’ve got 1 tens and 4 ones. 1 tens = 10 + 4= 14.

Your turn…. . Try this questions and then check your answer with my steps afterwards. 31 – 25 = To start, we draw the first number (the largest number) in our sum. 31 has 3 tens and 1 one. Then we look to cross out the second number. This time we have 2 tens and 5 ones to take away. Let’s start with the ones. We do not have 5 ones to take away. Tens Ones We need to break down a ten stick into ten ones. We cross out 1 ten and draw ten ones instead. Now we can cross out the 5 ones the question’s asked us to. We mustn’t forget to take away then tens in the question. I need to take away 2 more tens. Now, we count up what we have left. We must start with the ones. Then the tens. 0 6 We’ve got 0 tens and 6 ones. 0 tens = 0+ 6 = 6.

Let’s practise these skills on our activity sheet.