Numbers: An introduction to subtraction
Numbers: An introduction to subtraction

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: An introduction to subtraction

2 Subtracting in your head

To subtract one number from another without using a calculator you need to know basic subtractions up to 20. This means that you need to know, off by heart, what result you get if you subtract any number up to 10 from any bigger number up to 20. For example you have to remember that 14 minus 6 is 8, or 9 minus 5 is 4, and so on.

If you are confident that you know the basic subtractions up to 20, carry on with the rest of this course. If you are unsure, or would like some practice to help you remember them, then go now to Section 9 Subtracting small numbers by following the link on the left. Then return here to continue.

Sub_1

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 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