Approximation: Approximating values of addition and subtraction, multiplication and division.

Let's break down the problems step by step.

i. Solve and write in approximation form the basic operational system:

The basic operational system includes addition, subtraction, multiplication, and division. To approximate values, we can use rounding numbers to the nearest whole number or to one decimal place.

For example, let's consider the following operations:

• Addition: 4.7 + 2.3 ≈ 7 (rounded to the nearest whole number)
• Subtraction: 8.1 - 3.4 ≈ 5 (rounded to the nearest whole number)
• Multiplication: 4.2 × 2.5 ≈ 10 (rounded to the nearest whole number)
• Division: 9.6 ÷ 2.1 ≈ 5 (rounded to the nearest whole number)

ii. Round up some given numbers:

Let's round up the following numbers:

• 4.23 → 5 (rounded up to the nearest whole number)
• 7.81 → 8 (rounded up to the nearest whole number)
• 2.19 → 3 (rounded up to the nearest whole number)
• 9.46 → 10 (rounded up to the nearest whole number)

Note: When rounding up, we look at the decimal part of the number. If it's greater than 0, we round up to the next whole number. If it's 0, we leave the number as it is.

For JSS 1 students, it's essential to understand that approximation is a way of simplifying calculations by rounding numbers to a more manageable form. This skill is crucial in real-life applications, such as measuring ingredients for cooking, estimating distances, or calculating costs. By practicing approximation, students can develop their problem-solving skills and build a strong foundation in mathematics.