Reading big whole numbers
A whole number can be split into groups of three digits: ones, thousands and millions. Each digit sits in a place and shows a value. In 3 725 468 the digit 7 is in the hundred thousands place, so its value is 700 000.
Key idea
To round to the nearest thousand, look at the hundreds digit. If it is 5 or more, round up; if it is 4 or less, round down.
Rounding off
Worked example
Round 46 823 to the nearest thousand.
The hundreds digit is 8 (which is 5 or more), so round up.
46 823 → 47 000.
Number patterns
In a pattern like 4, 8, 12, 16, … each number is 4 more than the one before, so the next number is 20. A pattern can also go down, such as 30, 27, 24, … where each number is 3 less. Always find the rule first by comparing two numbers next to each other, then continue. To compare which whole number is bigger, first count the digits, then read from the left until the digits are different. The number with the larger digit in the highest place is the bigger number.
Remember
- Read numbers in groups of three from the right.
- Rounding: check the digit to the right of the place you want.
- Check a pattern rule with two or three terms before you use it.
- More digits usually means a bigger number.