Week 3 (w/c 4/5/20): Subtracting a single digit from a 20s number bridging 20 (Main Group)
This forms the basis of our class learning and our number facts for this week (see above)
Please complete pages 21 and 22 of NHM Booklet Addition and Subtraction to 100
Please complete symmetry pages 6 and 7 from NHM Booklet Shape, Measure and Data Handling.
I have put quite a few symmetry resources here from twinkl...please don't feel obliged to do them all. Have a chat with your P3 to see which would be more appropriate to his/her ability/interest level.
Week 4 (w/c 11/5) Finding a Small Difference by Counting On (Both Groups)
This is a very useful clip to watch (for parents/carers) before beginning this week's subtraction activities.
This is a useful clip to show your P3 when beginning to practise the counting on strategy for finding a small difference (both groups).
Week 4 - Measuring in centimetres (both groups)
Please complete page 11 in NHM Booklet 'Shape, Measure and Data Handling'. Children have to estimate and then measure in centimetres. For children, the biggest obstacle to measuring correctly is placement of the ruler. You will be amazed and amused at all the different ways children can get this wrong!
To start week 5 we will be practising subtracting 10. We do this practically by looking at tens and ones. To subtract ten from any 2-digit number we take away 'a ten stick'. As a substitute for ten sticks and cubes you can use 10p and 1p coins. The most important thing for your P3 to notice is that when 10 is taken away the 'ones' stay the same and the tens decrease by 1
Please watch these videos with your P3....
Once you've watched these clips please have a go for yourselves using 10p and 1p coins and/or using your own improvised ten sticks and ones.
The following PDF is a fun game to help practise subtracting 10.
This week the 'Main Group' will be beginning to look at subtracting a 2-digit number from another 2-digit number. Like most of the subtraction this month this might prove difficult. With lots of practise, initially using concrete materials or the 100 square, P3s should eventually feel more comfortable with this. Please don't panic if your P3 is struggling with this.....it's really hard! They will practise this the whole way through school so there's no need to be an expert just yet. The ones (units digit) that we take away this week will ALWAYS be smaller than the one we take from. It's important to mention that in P3 we don't start 'column/vertical subtraction'. In P3 we practise using tens and units and doing subtraction mentally/horizontally.
This week the 'Small Group' will be subtracting a multiple of 10 from another multiple of 10. This builds on the work done in week 3 when they were subtracting 10 from a multiple of ten. Obviously this also links to subtraction of single digits. For example they know that 5-2=3 and so it follows that 50-20=30 (or 5 tens minus 2 tens equals 3 tens.)
To begin the week it is helpful to revise subtracting a 'tens number' (10,20,30 etc.) from a 2-digit number. Remember that when taking away tens the ones (units) stay the same. Focus on the tens column and take away tens, one at a time:
eg. 56 - 20=
56 -10 -10=
eg. 72 - 30 =
72 - 10 - 10 - 10 =
In place of ten sticks and ones, please improvise with whatever you have.....eg pens for 10 sticks and cheerios for ones!
Please also have a good look at the 100 square. Carol Vorderman does a good lesson on taking away multiples of 10 on Maths Factor (your P3s each have their own login for this - it's the same as bugclub). I'll post the link below. There's a quick explanation from Carol and then a warm up and some written questions.
When your P3 is ready you can try taking away any 2-digit number from another. Take away the ones/units first and then the tens. Use your tens and ones or your 100 square(counting backwards to take the ones off and then counting vertically up to take off the tens) at first then eventually move to the written method, doing the calculations mentally. For example:
63 - 21 =
63 - 1 - 10 - 10 =
75 - 33 =
75 - 3 - 10 - 10 - 10 =
Please complete pages 27 and 28 in NHM Booklet Addition and Subtraction to 100.
The best way to begin is to use 10p coins to demonstrate taking away 10s from a tens number. Eg Using 10p coins:
50p (5 tens) - 30p (3 tens) = 20p (2 tens)
Repeated practice of this will reinforce the link between tens subtraction and their knowledge of single digit subtraction.