Maths
Whole numbers
Numbers are part of everyday life. It is important that you can write and describe them, and carry out simple calculations without using a calculator.
This Revision Bite covers:
In the number 3 147 286 the figure 2 has a value of 200 (two hundred), and the figure 3 has a value of 3 000 000 (three million).
What is the value of the figure 8 in 3 147 286?
The figure 8 has a value of eight tens, or 80.
When describing whole numbers, remember the place values of the original digits.
However, some digits are 'joined' in their description. For example - when describing the number 35, we do not say 'three tens and five units', but instead describe it by the more common name of 'thirty five'.
In the same way the thousands, ten-thousands and hundred-thousands columns are usually described together. Here are some examples.
2 000 is described as 'two thousand'
62 000 is described as 'sixty two thousand', and
162 000 is described as 'one hundred and sixty-two thousand'
The number 3 147 286 can be written in words as
three million, one hundred and forty seven thousand, two hundred and eighty six.
Q1. Describe the numbers 4 235 225 in words.
Q2. Write twenty-three thousand and fifty six in figures
A1. Four million, two hundred and thirty five thousand, two hundred and twenty five.
A2. 23 056
When you have a series of large numbers that are not in number order, it is sometimes difficult to make sense of them.
Here is a table showing the daily profits of an online music store, written in order of days:
Day | Mon | Tues | Weds | Thurs | Fri | Sat | Sun |
---|---|---|---|---|---|---|---|
Profit | £5934 | £7656 | £7573 | £8678 | £10834 | £14976 | £5004 |
If these numbers were put into a place value table, it would be easier to arrange them in order.
Days | Tens of thousands | Thousands | Hundreds | Tens | Units |
---|---|---|---|---|---|
Mon | 5 | 9 | 3 | 4 | |
Tues | 7 | 6 | 5 | 6 | |
Weds | 7 | 5 | 7 | 3 | |
Thurs | 8 | 6 | 7 | 8 | |
Fri | 1 | 0 | 8 | 3 | 4 |
Sat | 1 | 4 | 9 | 7 | 6 |
Sun | 5 | 0 | 0 | 4 |
Look at each column in turn.
The figures for Friday and Saturday will be the largest as these have figures in the tens of thousands column.
Looking at the thousands column shows that there is a 4 in the thousand column for Saturday and a 0 in the thousands column for Friday. Therefore Saturday has the largest number.
Here is the table written in order of days:
Day | Sat | Fri | Thurs | Tues | Weds | Mon | Sun |
---|---|---|---|---|---|---|---|
Profit | £14976 | £10834 | £8678 | £7656 | £7573 | £5934 | £5004 |
When we multiply by 10, every figure moves one place to the left. Units become tens, tens become hundreds and hundreds become thousands.
When we multiply by 100, every figure moves two places to the left. Units become hundreds, tens become thousands and hundreds become ten-thousands.
When we multiply by 1000, every figure moves three places to the left. Units become thousands, tens become ten-thousands, and hundreds become hundred-thousands.
When we divide by 10, every figure moves one place to the right. Thousands become hundreds, hundreds become tens and tens become units.
When we divide by 100, every figure moves two places to the right. Thousands become tens, hundreds become units, and tens and units become fractions of a unit.
When we divide by 1000, every figure moves three places to the right. Thousands become units. Hundreds, tens and units become fractions of a unit.
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