M1.          (a)     5
1
(b)     – 3 OR minus 3
Accept ‘3 degrees below zero’ or similar OR –3’ written on either thermometer.
Do not accept ‘3–’ OR a mark on the thermometers such as a cross, unless the numerical answer is written.
1
[2]

 

M2.          
          OR

Accept alternative indications, eg the numbers crossed or underlined.
[1]

 

M3.          (a)     9
1
(b)     7
Accept –7
1
[2]

 

M4.          50
Accept –50
[1]

 

M5.          18
Accept –18
[1]

 

M6.          (a)     –10
Do not accept 10–
1
(b)     45
1
[2]

 

M7.(a)     −7°C
Do not accept 7−
1
(b)     13°C
If (a) is negative allow follow through in part (b)
for ONE mark.
1
[2]

 

E1.          (a)     No common errors were identified among children achieving levels 4 and 5 overall. However, about 15% of children working at level 3 recorded the temperature on one of the thermometers rather than finding the difference between the two. There was little difference in performance between girls and boys.
(b)     All children found this part of the question more difficult than the previous part. Children working at level 3 overall found the question much harder than children working at level 5. Boys found the question slightly easier than girls, at all levels.

A common error, given by about 5% of children achieving level 3 and a slightly higher percentage of children achieving level 4 was 11°C; this was given by children who misread the question as York being colder than Rome, rather than the other way round. Another common incorrect response among children achieving level 3 was 3°C. This was given by children who ignored the minus sign or took the smallest number from the largest number. Some children working at level 3 misread the question or thermometer and wrote the answer -7°C, while another common response among children at this level was 0° C. This answer was given by children who calculated a temperature that was seven degrees colder than the temperature for Rome in part (a).

E2.          This question assesses children’s ability to find a positive and a negative number, each with up to one decimal place, with a given difference.
More than 70% of children at level 4 and nearly 95% at level 5 gave a correct answer, for children at level 3 the figure was about one-third. Over 15% of children at level 3 omitted the question, which shows how difficult it was for these children.
There were two possible correct responses. At all levels the response ‘-1 and 1’ was much more common than ‘-0.5 and 1.5’.

For children at both levels 3 and 4 the most common error was to choose the numbers ‘0.5 and 1.5’. These numbers have a sum of two, rather than the required difference of two. This error was made by 15% of children at level 3 and 10% at level 4.

E3.          The first part of this question assesses children’s ability to read two thermometer scales and to find the difference between the two temperatures shown.
For the first part of this question, almost 90% of children at level 4 were successful, as were nearly all children at level 5. Two-thirds of children at level 3 were also correct.
Common incorrect responses made by children at level 3, were 10 and 11. The answer 10 suggests these children understood they had to find the difference between the two temperatures but may have included both end points in reading from the scale. For the second error, these children may have misunderstood the question and read 11 from the first thermometer. Less than 10% of children at level 3 made this error.

The second part of this question assesses children’s ability to find the difference between two negative temperatures.
For the second part of the question, success rates were higher for all levels. Over 90% of children at level 4 and level 5 answered correctly, as did 80% of those at level 3. Twice as many children at each level gave the answer 7 than the answer -7, which was acceptable for one mark.
The few errors seen were varied, with no common trends.

E4.          Target Level: 4
Curriculum Coverage (POS ref: Ma2/2c)
This question assesses children’s ability to find the difference between a positive integer and a negative integer, set in the context of temperature.

Performance
More than 75% of children working at level 4 gave the correct answer, as did nearly all of those working at level 5 and over one-third of those working at level 3.

Common errors and misconceptions
•    A common error made by over 15% of children working at level 4 and one-third of those working at level 3 was 10, which was reached by subtracting 20 from 30 rather than –30.
•    Almost 10% of children working at level 3 gave –10 as their answer, which was reached by subtracting 30 rather than –30 from 20.