Reading Clocks with Roman Numerals

Understanding Roman numerals is part of the maths national curriculum from 2014. Children in Year 3 will be expected to be able to tell the time on clocks that have Roman numerals. It is helpful for children to understand Roman numerals, as many clocks and watches have them.

In Year 4, children will be expected to be able to read Roman numerals up to 100, and 1000 in Year 5. They can learn how to do this HERE.

In order to tell the time, children need only to learn the Roman numerals for the numbers 1-12.

Roman numerals 1-12

You could just get your child to memorise each of these, but in order to have a better understanding of the system, which will help them when they have to learn higher numbers in the system in years 4 and 5, it is best to explain to them how the system works.

Start by explaining that, in the Roman numeral system, certain special numbers are represented by letters.

The special numbers are 1, 5, and 10 (also 50, 100, 500 and 1000, but we don’t need these in order to tell the time).

Here are the letters that stand for these numbers:

roman numerals 1, 5 and 10

Test your child by asking questions like ‘what does V stand for?’ ‘Which number is represented by the letter X’, etc. until you are happy that they are secure with which letter stands for each number and vice versa.

Ask your child how we might represent 2 with Roman numerals. Hopefully they will guess that 2 can be represented with two Is.

2 = II

Now ask them: “How about 3?”3 = III

Now ask them: “How about 4?”

Your child will logically answer IIII, but explain that with Roman numerals, when we get to a number that is one less than a ‘special’ number we do something different.

Tell them that because 4 is one less than 5, and 5 has its own special letter (V)… we show the number 4 like this:

4 = IV

Because the I is BEFORE the V, it shows that it is 1 LESS than V (5). This is quite a difficult concept for children to grasp, so make sure this is understood before moving on.

You could clarify this concept by explaining that whenever they see a letter that is lower in value to the LEFT of a higher value letter, then we subtract. Usually in Roman numerals, we see lower value letters to the RIGHT of the higher value letters.

Using this knowledge, ask your child how they think we will write the number 9 (remind them that ten is represented by the letter X).

Hopefully, they will be able to work out that 9 is IX.

Next, ask them what they think 6 might be.

Then 7, 8, etc. Explain that letters after a letter should be added to a letter.

Ask them: ‘What is the highest amount of Is together that you ever see?’

With Roman numerals, you will never see more than three of any letter together. It is important that they know this, as it is a way of them being able to check if they have written a Roman numeral correctly.

Tell them that 11 and 12 are generated in a similar way to 6 and 7. See if they can guess what letters will represent these numbers.

Go back to the beginning and ask your child to write the numbers 1 to 12 in Roman numerals… they should be able to do it if they remember the following points:

  • 1 is represented by the letter I.
  • 5 is represented by the letter V.
  • 10 is represented by the letter X.
  • All the numbers 1 to 12 can be made using just these three letters.
  • You never have more than 3 of any letters in a row.
  • When you come to the number BEFORE one that has a special letter for it, then you use that special letter and put an I before it to show that it is one less than the special number.

Check what your child has written against this chart:

Roman numerals 1-12

Well done if they got them all correct!well done imageThey can practise this skill more by playing this fun Roman numerals online game.

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