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PLEASE NOTE the problem was slightly changed in 2018 so that it was not a red circle in each of the 5 questions but a different red shape each time.

Joanne wrote:

In the first line the circle is worth 1.
I worked this out by adding 17 and 7 together = 24 then add 1 =25

In the second line the circle is worth 20.
I worked this out by adding together 17, 7, 7 =31 add 20 =51

In the third line the circle is worth 44.
I worked this out by adding together 17, 17, 7 and 7 =38

In the fourth line the circle is worth 16.
I worked this out by doing 48 divided by 3 =16

In the fifth line the circle is worth 27.5
I used the same method as the 1st, 2nd and 3rd lines.

Christopher and Matthew explain further about the final answer:

On the last one the total was 100. We had to add 17 + 7 + 7 + 7 + 7 = 45.
This meant there was 55 left which we halved to get the answer 27 and a half.

Matthew from Worth School agreed with the answers given above but has recorded his thinking differently:

I looked at it as an equation.

What Matthew already knows: Triangle = 7, Rectangle = 17 and he uses C = circle

1.
If 17+C+7=25 then C =?
This can be rearranged as:
25-(17+7)=C
25-24=C
1=C

2.
If 17+7+7+C=51 then C=?
This can be rearranged as:
51-(17+7+7)=C
51-31=C
20=C

3.
If 7+7+17+17+C+C=136 then C=?
This can be rearranged as:
136-(7+7+17+17)=2C
136-48=2C
88=2C
44=C

4.
If C+C+C=48 then C=?
This can be rearranged as:
48=3C
48/3=C
16=C

5.
If 7+C+7+17+7+C+7=100 then C=?
This can be rearranged as:
28+17+2C=100
45+2C=100
2C=100-45
2C=55
C=27.5

Thank you also to sets of Moorfield pupils, Niall and Adam , Steven and Matthew, Christopher, Elliot and Luke, Hannah, Amy and Emma, Thomas and Robert , as well as to Abi . From Ms Flynn's class in Ringmer County Primary in Sussex, we heard from Nick and Tom. Ellen, Stacie, Rosie and Natasha from St. Aldhelm's Combined School all sent in the mail their calculations to this set of problems. Carla and Georgia from Tattingstone Primary School in Suffolk both sent their work as email attachments. Well done also to Mithran .
Each one of you put a lot of effort into your work and your explanations were clear and well thought-out.