Place value (Edexcel GCSE Maths): Revision Notes
Place value
Place value is the system that determines how much each digit in a number is worth based on where it sits in that number. This is a fundamental concept that helps us understand and work with all types of numbers, especially when dealing with money.
Understanding place value positions
Each position in a number has a specific value. As you move from right to left, each position becomes ten times larger.
Key place value positions you need to know:
- Units (ones) - the rightmost digit
- Tens - ten times bigger than units
- Hundreds - ten times bigger than tens
- Thousands - ten times bigger than hundreds
- Ten thousands - ten times bigger than thousands
The further left a digit appears, the greater its value becomes.
Worked Example: Breaking down 2,508
In the number 2,508:
- The 8 is worth 8 units
- The 0 is worth 0 tens
- The 5 is worth 5 hundreds (500)
- The 2 is worth 2 thousands (2,000)
Working with money and place value
When dealing with money, place value becomes especially important.
Essential money and place value rules:
- 100p = £1 - This conversion is crucial for all money calculations
- Always work in the same units throughout your calculation (either all pence or all pounds)
- Pounds need 2 decimal places - For example, write 280p as £2.80
- Write either £ or p in your answer, but never both together
Ordering numbers using place value
To arrange numbers in order from smallest to largest, compare digits from left to right:
- Start with the leftmost digit (highest place value)
- If digits are the same, move one position right
- Continue until you find a difference
- The number with the smaller digit in that position is smaller overall
Worked Example: Ordering £925, £2908, £2950, £5011, £10430
Step-by-step ordering process:
- £925 comes first (smallest thousands digit)
- £2908 and £2950 both start with 2, so compare hundreds: 9 vs 9
- Then compare tens: 0 vs 5, so £2908 comes before £2950
- Continue this process for all numbers
Final order: £925, £2908, £2950, £5011, £10430
Exam tips
Important exam strategies:
- Show your working clearly - examiners can award partial marks even if your final answer is wrong
- Copy numbers carefully from the question - small errors can cost you marks
- Read questions thoroughly - make sure your final answer matches what's being asked (number of items, not just the calculation)
- Check your units - ensure you're working consistently in pounds or pence throughout
Key Points to Remember:
- Place value determines digit worth - the same digit can be worth different amounts depending on its position
- Left digits are worth more - moving left increases value by factors of ten
- Money conversions matter - always remember that 100p = £1
- Use correct decimal places - pounds always need 2 decimal places (e.g., £2.80, not £2.8)
- Compare from left to right - when ordering numbers, start with the highest place value positions