1. **Rounding off 435 673 to the nearest 5** The problem asks to round 435 673 to the nearest 5. Rule: To round to the nearest 5, look at the last digit and round to the closest multiple of 5. Step 1: The last digit is 3. Step 2: The multiples of 5 near 3 are 0 and 5. Step 3: 3 is closer to 5 than 0, so round up. Answer: 435 675 2. **Factors of 8 and 12 and HCF** Step 1: Factors of 8 are numbers that divide 8 exactly: 1, 2, 4, 8 Step 2: Factors of 12 are: 1, 2, 3, 4, 6, 12 Step 3: Common factors of 8 and 12 are: 1, 2, 4 Step 4: Highest Common Factor (HCF) is the greatest common factor: 4 3. **LCM of 60 and 80** Step 1: Prime factorize both numbers: $$60 = 2^2 \times 3 \times 5$$ $$80 = 2^4 \times 5$$ Step 2: Take the highest powers of all primes: $$2^4, 3^1, 5^1$$ Step 3: Multiply: $$LCM = 2^4 \times 3 \times 5 = 16 \times 3 \times 5 = 240$$ 4. **Ratio of boys to girls is 2:4** 3.1.1 Simplify the ratio: Divide both terms by 2: $$\frac{2}{2} : \frac{4}{2} = 1 : 2$$ 3.1.2 Number of boys: Total learners = 42 Ratio parts = 1 + 2 = 3 Each part = $$\frac{42}{3} = 14$$ Number of boys = 1 part = 14 3.1.3 Number of girls = 2 parts = $$2 \times 14 = 28$$