MARKING SCHEME FOR JSS1 MATHEMATICS SECOND TERM EXAMINATION

SECTION A: OBJECTIVE TEST

ALLOCATION OF MARKS: ½ mark each = 30 marks

SECTION B: ESSAY

ALLOCATION OF MARKS: 30 marks

SUB-SECTION 1

1.(a) \(6\frac{1}{4} + 1\frac{1}{2} -2\frac{1}{4}\)  (1 mark)

\(= \frac{5(1 + 2 -1)}{4}\) (2 marks)

\(= 5 \frac{2}{4}\)  (1 mark)

\(= 5 \frac{1}{2}\)  (2 marks)

1.(b) \(\frac{7}{12}, \frac{2}{3}, \frac{3}{4}, \frac{5}{8} = \frac{14, 16, 18, 15}{24}\)  (2 marks)

\(∴ \frac{3}{4}, \frac{2}{3}, \frac{5}{8}, \frac{7}{12}\) in descending order  (2 marks)

(TOTAL = 10 MARKS)

2.(a) \(72.00\) as a percentage of \(360.00\)  (1 mark)

\(= \frac{72}{360} × \frac{100}{1}\)  (2 marks)

\(= 20\%\)  (2 marks)

2.(b) \(10011_{two} = 1×2^4+0 ×2^3+ 0 × 2^2+ 1× 2^1 + 1 × 2^0\)  (1 mark)

\(= 1×16+0×8+ 0 × 4 + 1× 2 +1 × 1\)  (2 marks)

\(= 16 + 0 + 0 + 2 +1\)  (1 mark)

\( = 19\)  (1 mark)

(TOTAL = 10 MARKS)

SUB-SECTION 2

1.(a) \(5y + 3 = 18\)

Collect the like terms

\(5y = 18 -3\)  (½ mark)

\(5y = 15\)  (½ mark)

Divide both sides by \(5\)

\(\frac{5y}{5} = \frac{15}{5}\)  (½ mark)

\(Y = 3\)  (1 mark)

1.(b) \(a + 2(a + 3) = 36\)

\(a + 2a + 6 = 36\)  (½ mark)

\(3a + 6 = 36\)

Collect like terms

\(3a = 36 -6\)  (½ mark)

\(3a = 30\)  (½ mark)

Divide both sides by \(3\)

\(\frac{3a}{3} = \frac{30}{3}\)  (½ mark)

\(a = 10\)  (½ mark)

(TOTAL = 5 MARKS)

2.(a) The sum of two consecutive even numbers is \(22\).