Soalan 2:
Hitung setiap operasi berikut. Nyatakan jawapan betul kepada angka bererti yang dinyatakan dalam kurungan.
(a) 2.57 × 4.5 + 0.45 [4]
(b) 8.59 ÷ 2.1 – 1.26 [3]
(c) 14.23 – 2.6 × 1.2 [3]
(d) 15.74 + 20.3 ÷ 2.5 [2]
(e) 7.63 × 0.5 ÷ 4.2 + 5.7 [3]
(f) 10.25 ÷ 0.75 – 4.2 × 0.2 [2]
(g) 15.62 – 1.72 × 0.2 + 6.3 [1]
(h) 4.94 + 5 .76 ÷ 0.26 × 1.4 [3]
Penyelesaian:
(a)
$$ \begin{aligned} & 2.57 \times 4.5+0.45 \\ & =(2.57 \times 4.5)+0.45 \\ & =11.565+0.45 \\ & =12.015 \\ & =12.02(4 \text { a.b. }) \end{aligned} $$
(b)
$$ \begin{aligned} & 8.59 \div 2.1-1.26 \\ & =(8.59 \div 2.1)-1.26 \\ & =4.0905-1.26 \\ & =2.8305 \\ & =2.83(3 \text { a.b. }) \end{aligned} $$
(c)
$$ \begin{aligned} & 14.23-2.6 \times 1.2 \\ & =14.23-(2.6 \times 1.2) \\ & =14.23-3.12 \\ & =11.11 \\ & =11.1(3 \mathrm{a} . \mathrm{b} .) \end{aligned} $$
(d)
$$ \begin{aligned} & 15.74+20.3 \div 2.5 \\ & =15.74+(20.3 \div 2.5) \\ & =15.74+8.12 \\ & =23.86 \\ & =24(2 \mathrm{a} . \mathrm{b} .) \end{aligned} $$
(e)
$$ \begin{aligned} & 7.63 \times 0.5 \div 4.2+5.7 \\ & =[(7.63 \times 0.5) \div 4.2]+5.7 \\ & =(3.815 \div 4.2)+5.7 \\ & =(0.90833)+5.7 \\ & =6.60833 \\ & =6.61(3 \text { a.b. }) \end{aligned} $$
(f)
$$ \begin{aligned} & 10.25 \div 0.75-4.2 \times 0.2 \\ & =(10.25 \div 0.75)-(4.2 \times 0.2) \\ & =13.667-0.84 \\ & =12.827 \\ & =13(2 \text { a. b. }) \end{aligned} $$
(g)
$$ \begin{aligned} & 15.62-1.72 \times 0.2+6.3 \\ & =15.62-(1.72 \times 0.2)+6.3 \\ & =15.62-0.344+6.3 \\ & =21.576 \\ & =20(1 \text { a.b. }) \end{aligned} $$
(h)
$$ \begin{aligned} & 4.94+5.76 \div 0.26 \times 1.4 \\ & =4.94+[(5.76 \div 0.26) \times 1.4] \\ & =4.94+(22.154 \times 1.4) \\ & =4.94+31.0156 \\ & =35.9556 \\ & =36.0(3 \mathrm{a} . \mathrm{b} .) \end{aligned} $$
Hitung setiap operasi berikut. Nyatakan jawapan betul kepada angka bererti yang dinyatakan dalam kurungan.
(a) 2.57 × 4.5 + 0.45 [4]
(b) 8.59 ÷ 2.1 – 1.26 [3]
(c) 14.23 – 2.6 × 1.2 [3]
(d) 15.74 + 20.3 ÷ 2.5 [2]
(e) 7.63 × 0.5 ÷ 4.2 + 5.7 [3]
(f) 10.25 ÷ 0.75 – 4.2 × 0.2 [2]
(g) 15.62 – 1.72 × 0.2 + 6.3 [1]
(h) 4.94 + 5 .76 ÷ 0.26 × 1.4 [3]
Penyelesaian:
(a)
$$ \begin{aligned} & 2.57 \times 4.5+0.45 \\ & =(2.57 \times 4.5)+0.45 \\ & =11.565+0.45 \\ & =12.015 \\ & =12.02(4 \text { a.b. }) \end{aligned} $$
(b)
$$ \begin{aligned} & 8.59 \div 2.1-1.26 \\ & =(8.59 \div 2.1)-1.26 \\ & =4.0905-1.26 \\ & =2.8305 \\ & =2.83(3 \text { a.b. }) \end{aligned} $$
(c)
$$ \begin{aligned} & 14.23-2.6 \times 1.2 \\ & =14.23-(2.6 \times 1.2) \\ & =14.23-3.12 \\ & =11.11 \\ & =11.1(3 \mathrm{a} . \mathrm{b} .) \end{aligned} $$
(d)
$$ \begin{aligned} & 15.74+20.3 \div 2.5 \\ & =15.74+(20.3 \div 2.5) \\ & =15.74+8.12 \\ & =23.86 \\ & =24(2 \mathrm{a} . \mathrm{b} .) \end{aligned} $$
(e)
$$ \begin{aligned} & 7.63 \times 0.5 \div 4.2+5.7 \\ & =[(7.63 \times 0.5) \div 4.2]+5.7 \\ & =(3.815 \div 4.2)+5.7 \\ & =(0.90833)+5.7 \\ & =6.60833 \\ & =6.61(3 \text { a.b. }) \end{aligned} $$
(f)
$$ \begin{aligned} & 10.25 \div 0.75-4.2 \times 0.2 \\ & =(10.25 \div 0.75)-(4.2 \times 0.2) \\ & =13.667-0.84 \\ & =12.827 \\ & =13(2 \text { a. b. }) \end{aligned} $$
(g)
$$ \begin{aligned} & 15.62-1.72 \times 0.2+6.3 \\ & =15.62-(1.72 \times 0.2)+6.3 \\ & =15.62-0.344+6.3 \\ & =21.576 \\ & =20(1 \text { a.b. }) \end{aligned} $$
(h)
$$ \begin{aligned} & 4.94+5.76 \div 0.26 \times 1.4 \\ & =4.94+[(5.76 \div 0.26) \times 1.4] \\ & =4.94+(22.154 \times 1.4) \\ & =4.94+31.0156 \\ & =35.9556 \\ & =36.0(3 \mathrm{a} . \mathrm{b} .) \end{aligned} $$