Numbers, units and arithmetic

This free course is available to start right now. Review the full course description and key learning outcomes and create an account and enrol if you want a free statement of participation.

Free course

# 1.3 Using the place value

Writing numbers in place-value columns gives an easy way of multiplying by 10, 100, 1000 and so on. Have a look at the place value table again.

Notice that moving all the digits one column to the left in the table (and adding a zero to the units column) is the same as multiplying by ten; for instance, ten tens are a hundred, ten hundreds are a thousand. If you move two columns to the left, you multiply by a hundred; for instance, a hundred tens are a thousand. Moving three columns to the left is equivalent to multiplying by a thousand, and so on.

## Example 2

After local government re-organisation a new council expects to receive cash payments in ten instalments from about 26 000 households. In order to negotiate the cash collection at post offices it needs to know how many payments are made altogether in a year. How many are there likely to be?

### Answer

The total number of payments is the number of households times the number of payments per household, i.e. 26 000 × 10. This can be worked out by moving all the digits of 26 000 one place to the left, and adding a zero at the end:

So 26 000 × 10 = 260 000.

A total of 260 000 cash payments should be expected.

MU120_4M1

### Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has nearly 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to university level study, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus