Numbers, units and arithmetic
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

Numbers, units and arithmetic

3.6.2 Try some yourself

Activity 36

Without using your calculator, find the following:

  • (a) 100.001 + 10.1

  • (b) 100.001 − 10.1

Answer

  • (a)

  • (b)

Activity 37

Suppose you went shopping with a friend and your combined bill came to £85. You knew that you had spent £47.65. What was your friend's share of the bill?

Answer

Your friend's share of the bill is £85 − £47.65 = £37.35. There are many ways to do this subtraction. Setting out as a formal sum is one approach, but counting on (as an assistant may do to give change) is another (from £47.65 a further 35 p is needed to make £48, then £2 to make £50 and £35 to make £85 gives £37.35).

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 over 40 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