In mathematics, the first relationship that we learn about is equality, where an expression on the left hand side of the equal sign is equal to an expression on the right hand side of the equal sign

• For example:
  • 4 – 1 = 3
  • 5 – 4 = 3 – 2
  • 7²=49

Things are not always equal though. We can never write 3=7.

So in mathematics we have other symbols, which we can think of as “crocodiles” that we use to indicate that things might not be equal. These symbols are: <, ≤, > and ≥.

For instance 5>3, 2<7.

When we are dealing with decimals we need to think about the place value of the digits to see clearly which numbers are bigger. What are the place value of each of the digits in the following number: 123.456? Which of the digits has the largest value.

So, which is bigger, 4.2 or 4.09998? Can you use a “crocodile” to write your answer? What are the two different ways that you could write it?

Let’s have a go at the following questions, from exercise 5C on pages 73 and 74:

The answers to the exercise are below: