Examinations Council of Lesotho 2023 Examiner’s report Mathematics Paper 1 (0178/01) 2023 – 0178/01 Examiner’s Report 1 Mathematics (0178/01) October/November 2023 Report to Schools Introduction This report serves to share information on the examiners’ observations during the marking of Mathematics paper 1 (0178/01) in the November 2023 examinations. The document gives comments on the candidates’ general performance, strengths and weaknesses. Problematic topics and areas on which teachers must put emphasis are also highlighted. It provides detailed feedback on individual questions by stating the expected responses, candidates’ common responses (errors), misconceptions and recommendations where necessary. General comments Most candidates showed a good performance in this paper, some candidates did not answer what was asked for in the question. This was seen even when candidates clearly understood the topic, particularly in question 6 in which depreciation was often given as the answer while the question asked for the value of the car after one year’s depreciation. In question 4 learners would give one year’s interest instead of the investment period. Question analysis based on candidates’ responses Question Total marks Performance 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 3 4 4 3 2 2 3 3 3 4 4 4 3 4 4 3 2 2 3 60 Fair Poor Poor Poor Good Fair Good Poor Poor Fair Poor Fair Fair Fair Poor Fair Fair Fair Fair Total 2023 – 0178/01 Examiner’s Report 2 1 Evaluate (a) 3.6 ÷ 0.03 # # (b) 3 $ × 3 & Expected responses: (a) 120 (b) 10 Candidates’ common errors: (a) 0.12, 12, 1.2 (b) un-simplified working In (a) candidates found it challenging to convert decimals into whole numbers by multiplying by the powers of 10. For those who managed to convert decimals to fractions struggled to multiply by the reciprocal of the second fraction. In (b) most candidates managed to convert mixed fractions into improper fractions. However, they did not simplify the resulting fractions. #( The common result was # . Also, some candidates tried to find common denominator even )& & though the operation involved was multiplication, $ × & × #* & $ × $. Recommendations: Teachers should give more practice on teaching four basic operations on all types of numbers, making it clear to learners as to which operations require finding the LCM. Conclusion: The question was fairly done. 2 (a) By rouding each number in the calculation correct to one significant figure, estimate the value of (b) 5.62 × 230 0.34 Express 360 as a product of its prime factors. (b) 23 × 32 × 5 Expected responses: (a) 4000 Candidates’ common errors: (a) 400, 12, 1200 (b) various wrong responses (a) Most candidates failed to round off 0.34 and 5.62 to one significant figure. As a result, numerical expressions like *.(( × )(( *.(( × ) *.(( × )(( ( , (.,( , (.,( were frequent on the working space. (b) Numerous Misconceptions: (a) Most candidates treated division by zero and one equally alike. Therefore, evaluating *.(( × )(( ( yielded 1200. Recommendations: Teachers should teach students place values and rules of counting significant figures. Besides, teachers should strongly stress that division by zero is undefined. Teachers should also teach learners to draw the difference between prime and composite numbers. Conclusion: Poorly done 2023 – 0178/01 Examiner’s Report 3 3 (a) P = 3.6 × 103 and Q = 1.2 × 102. Calculate P – Q, giving your answer in standard form. 0 , (b) Evaluate /3 $ . # Expected responses: (a) 3.48 × 103 (b) 1 ) )2 Candidates’ common errors: (a) 3480, 2.4 × 10n (b) $ (a) Some candidates managed to convert the given numbers to ordinary form, however they could not take the difference back to the standard form as required by the question hence the result 3480. A sizeable number of candidates subtracted the coefficients irrespective of powers of 10 having different exponents. (b) Most candidates managed to change the mixed fraction into an improper one but failed to apply the third root appropriately. Recommendations: Teachers should include nth roots of fractions so as to widen the candidates’ learning scope. Conclusion: Poorly performed 4 Dlomo invests M8000 in the bank which offers simple interest at the rate 3% per annum. Calculate the number of years for which Dlomo will get a total interest of M1200. Expected responses: 5 years Candidates’ common errors: Most candidates evaluated an interest for a year, being M240, but failed to relate M240 with total interest i.e. M1200. For those who managed to 31200 relate, they could not divide correctly 3240 . A few candidates could not differentiate the principal amount from the total interest on the given information. Recommendations: Teachers should treat financial mathematics/commercial arithmetic topic in depth and give learners more practice problems of which the selected examples should include problems at synthesis level to widen the learners thinking scope. Conclusion: poorly done. 5 The interior angle of a regular polygon is 108°. Calculate the number of sides of the polygon. Expected response: 5 Candidates’ common errors: Most of the candidates got 72°. For those who went further failed to go extra mile in using 72° to find number of sides of such given polygon. 2023 – 0178/01 Examiner’s Report 4 Recommendations: Teachers should encourage candidates to regularly attempt problems involving interior and exterior properties. Conclusion: Well performed. 6 A car is valued at M320 000. The car depreciates by 5% every year. Calculate the new value of the car at the end of the first year. Expected responses: 304 000 &% Candidates’ common errors: 16000, 1600 or 320000 × #(( & Most of the candidates failed to multiply out or simplify 320000 × #(( on which they, in large numbers, got 1600. Recommendations: Teachers should emphasise the importance of simplifying before multiplying so as to minimise the chances of working with large numbers. Conclusion: Fairly done 7 −1 A=8 2 3: 3 2: and B = 8 5 1 0 Find (a) 3B, (b) A – B. Expected responses: (a) ;<, *(= Candidates’ common errors: (a) ;<, *,= (b) ;–?# &#= (b) ;?# #&= Most candidates did not manage to multiply or add correctly. Misconceptions: Some candidates treated 0 and 1 equally alike in their operations and thereafter got challenged by directed numbers. Candidates missed 3 × 0 and – 1 − 3 which let to loss of marks. Recommendations: Teachers should deal with directed numbers frequently in their calculations. Conclusion: Fairly done 8 Solve 2@ A 1 3 = @B2 4 . Expected responses: 2 2023 – 0178/01 Examiner’s Report 5 Candidates’ common errors: Most candidates still had divided by 12 even at the stage the denominators are no more expected ?()@ A #) E ,(@ B )) #) or partial multiplication of numerator terms by the LCM which led into incorrect responses. Recommendations: Equations and expressions should be well differentiated. Conclusion: Poorly done Expected responses: (a) 6 , (b) ? Candidates’ common errors: Most candidates got sin 6 as their answer simply because they failed to relate 10 and 5 as hypotenuse from the given ratio or Pythagorean triples to find the wanted side. Recommendations: Teachers should raise awareness into the learners thinking on the application of Pythagorean triples from the basic one, 3, 4, and 5. Conclusion: Poorly done. 10 Factorise completely. (a) 8𝑥 ) −50 (b) 𝑥 ) −5𝑥 −6 Expected responses :(a) 2(2𝑥 − 5)(2𝑥 + 5) Candidates’ common errors: (a) 2(4𝑥 ) − 25) 2023 – 0178/01 Examiner’s Report (b) (𝑥 − 6)(𝑥 + 1) (b) −6, −5, 1 6 In (a), most candidates factorised partially and did not realise that the resulting bracket consisted of difference of two squares which needed further factorisation, hence 2(4𝑥 ) − 25) was common. In (b), most candidates failed to choose the correct pair on the factors of whose sum is −5 instead they only focused on the pair of numbers whose sum is −5 or product of −6. Misconceptions: Most of the candidates got a variety of incorrect answers as an implication that they did not factorise the given expression correctly. Recommendations: Better emphasis is needed in factorisation but more especially on the difference of 2 squares when the coefficient of 𝑥 2 is greater than one. Also, teachers should caution candidates on the best way to choose correct factors which can be used in grouping the terms of the expressions before engaging in factorisation process. Conclusion: Fairly done 11 Mr Phela has 120 animals which are cows, horses and goats. 20% of the animals are cows. (a) This information is drawn on a pie chart. Calculate the sector angle which represents the number if cows. (b) One animal is chosen at random from Mr Phela’s animals. Calculate the probability that the animal chosen is either a horse or a goat. Expected responses: (a) 720 (b) ? & Candidates’ common errors: 24 (a) Most candidates calculated the number of cows instead of the sector angle for the number of cows as a result 24 was common. Recommendations: for (a), teachers should emphasise that the frequency is directly proportional to the sector angle. While for (b), teachers should show the importance of linking percentages, frequencies, and sector angles to probability. Conclusion: Poorly done 2023 – 0178/01 Examiner’s Report 7 Expected responses: (a) 90 360 × 22 7 ×7×7 = 1 4 × 22 × 7 = 11 × 7 ) = 77 2 =38.5 cm2 (AG) (b) 45.5 cm2 Candidates’ common errors: In (a) most candidates substituted correctly into the sector area equation but did not manage to simplify to the given answer. In (b), most candidates got the area of a rectangle correct earning a part mark. There were a handful of candidates who got incorrect answer due to failure to subtract decimals from whole numbers. 46.5cm2 was common. Recommendations: Teachers should include formulae of different polygons, both regular and irregular, in order to develop a deeper understanding on the candidates to calculate area. Conclusion: Fairly done 2023 – 0178/01 Examiner’s Report 8 13 Solve the simultaneous equations. 𝑥 + 2𝑦 = 7 2𝑥 + 3𝑦 = 8 Expected responses: 𝑥 = −5 𝑦=6 Candidates’ common errors: Most candidates did not multiply both sides of the equation when eliminating variables of their choice. However, for those who opted for substitution method could not proceed beyond substitution stage. Recommendations: It should be drawn to learners’ attention that in solving equations whatever is done to the left hand side should also be done to the right. Conclusion: Fairly done Expected responses: (a) Angle CBT 60°, reason: Tangent to the circle is perpendicular to diameter (b) Angle BAC 60°, reason: Angles in a triangle Candidates’ common errors: Most candidates were able to find wanted angles but failed to link those angles to their corresponding properties. 2023 – 0178/01 Examiner’s Report 9 Misconceptions: Instead of stating circle theorem, they showed how those angles are calculated. Recommendations: Strong emphasis is needed on angle properties. Conclusion: Fairy done 15 The table shows the ages of 30 boys. Age 10 11 12 13 14 Frequency 18 2 5 2 3 (a) Find the modal age. (b) calculate the mean age. Expected responses: (a) 10 Candidates’ common errors: (a) 18,12 (b) 11 (b) 10,12 In (b), few candidates managed to get a correct answer. Most candidates got incorrect products of variable and frequency. Misconceptions: (a) Majority of candidates chose mode as 18 simply because 18 is the largest number in the table. (b) Few candidates could not calculate the mean correctly from the frequency table. They treated each variable as having a frequency of 1 which led to dividing the sum of variables #( B ## B #) B #, B #? by 5. Thus, & = 12. Recommendations: Teachers should emphasise that mode is the variable that has the largest frequency. Teachers should include calculations of measures of central tendency from frequency tables regularly. Conclusion: Poorly performed. 16 A straight line passes through the points P(0,3) and Q(−2,1). (a) Find the gradient of the line PQ. (b) Write the equation of the line. Expected responses: (a) 1 (b) 𝑦 = 𝑥 + 3 Candidates’ common errors: for (a) There were multiple responses. Most candidates were challenged by the use of gradient formula with directed numbers involved. In (b) some candidates went on to calculate 𝑦 −intercept even though it was already evident on one of the coordinates. 2023 – 0178/01 Examiner’s Report 10 Recommendations: Teachers should encourage students to pay more attention to the way they substitute values of 𝑥 and 𝑦 into the gradient formula. Additionally, teachers should expose learners to the use of different commanding words in questions. Conclusion: Fairly done Expected responses: 300 Candidates’ common errors: 60 and 120 Recommendations: Teachers should integrate angle properties with bearings. They should also emphasise the direction in which the bearing is measured. Conclusion: Fairly done. 18 f(𝑥) = 3 −𝑥. Find f(−2). Expected responses: 5 Candidates’ common errors: Most candidates got challenged by 2 consecutive negative signs and ended up with subtraction 3 – 2 = 1 or multiplying as opposed to adding which let them to 6. Recommendations: Teachers should deal with directed numbers in many calculations. Apart from that, teachers should teach learners the difference between evaluating a function at a given constant (f(𝑘)) and f(𝑥)= 𝑘. Conclusion: Teacher should dig deeper on evaluating functions, not only using positive integers but even the negative ones. 2023 – 0178/01 Examiner’s Report 11 Expected responses: (a) 910 ± 1 (b) Angle bisection with construction of arcs Candidates’ common errors: (a) Numerous angles out of expected range of answer (b) Inaccurate angle bisection, bisection without arcs Recommendations: In (a), teachers should instil the skill of accurately measuring the angles into learners. For (b), teachers should enforce neat non free hand work in construction. 2023 – 0178/01 Examiner’s Report 12 Conclusion: Fairly performed Conclusion and recommendations To succeed in this paper, the entire core syllabus ought to be covered. Candidates should remember formulae and apply them appropriately and give answers in the form required. Candidates should use suitable level of accuracy where necessary. Teachers should complete the syllabus timeously so that learners can have adequate practice and exposure to examination type questions. Candidates in preparation for examination should be made aware that more than 1 mark generally indicates that progress towards a correct solution may be credited and as such workings should be clearly shown. 2023 – 0178/01 Examiner’s Report 13
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