Understanding Powers and Significant Figures in OCR GCSE Maths
When working with OCR Maths Paper 6 problems involving powers and significant figures, it's crucial to understand the fundamental concepts. Let's break down these mathematical operations step by step to ensure complete comprehension.
Definition: Significant figures are the digits in a number that carry meaningful value, starting from the first non-zero digit from the left. For example, in 326.8, all digits are significant.
In examining calculations like 326.8 × 6.94−3.4 ÷ 59.4, we must first understand how to approach such complex expressions. When rounding to one significant figure, we follow a systematic process: 326.8 becomes 300, 6.94 becomes 7, 3.4 becomes 3, and 59.4 becomes 60. This estimation technique helps verify if final answers are reasonable.
Working with powers requires understanding exponential notation and the laws of indices. For expressions like a⁵ × a3², we apply the multiplication rule of indices. When multiplying terms with the same base, we add the powers. In this case, a⁵ × a3² becomes a⁵ × a⁶ = a¹¹, demonstrating how index laws simplify complex expressions.
Example: When expressing numbers as powers of other numbers, like writing 125 as a power of 5, we can use this method:
- 125 = 5³ because 5 × 5 × 5 = 125