Multiplying is really a short form of repeated addition, so that instead of writing 7 + 7 + 7 + 7 + 7, we can just write 5×7.

If we are multiplying integers where one of them or both of them is negative, we can use the following multiplication table. Copy it in your book and memorise it. It will also work for dividing.

Let’s use it to find some products with the teacher.

Exercise

Let’s complete exercise 1D on page 12. Don’t worry about the multiplication table mentioned on question 3. You can answer the question without it.

The answers are below:

Division

A little like with addition and subtraction, we can think of multiplication and division as inverse operations, that is, operations which undo each other. So that -7 + 9 – 9 = -7. Also -4 x 8 ÷ 8 = -4.

This is demonstrated below:

Exercise

Let’s complete question 8 of exercise 1C on page 11 and then all of exercise 1E on pages 12 and 13:

The answers are below: