Roman Numerals and Negative Numbers
In Year 4, children meet two number ideas that sit just outside the everyday counting they already know. They learn to read Roman numerals from I to C, the letters used on clock faces, book chapters and old buildings, and they learn to count backwards past zero into negative numbers, the kind they see on a cold weather forecast. Both ask a child to read numbers in a new form and to keep counting in order even when the numbers feel unfamiliar.
Practise Roman Numerals and Negative Numbers
Have a guess, even if you're not sure. Get one wrong and we'll show you why, so every miss is a chance to learn.
Timed practice
The same practice, just with a gentle clock. Pick a length and see how many you can answer.
Good to know
The Roman numerals
Roman numerals are letters that stand for numbers. These are the ones to know, and the four that work backwards.
Counting through zero
Below zero the numbers carry on, just the other way. The further left you go, the smaller the number gets. On a thermometer that means colder, so minus 6 is colder than minus 2.
For grown-ups
Roman numerals are built from a small set of values: I is 1, V is 5, X is 10, L is 50 and C is 100, which are added up from left to right, with the one twist that a smaller letter placed in front of a bigger one is taken away, so IV is 4 and XC is 90. Negative numbers extend the number line in the other direction, so the further left of zero you go, the smaller the number becomes, and minus 5 is colder, and lower, than minus 2. Reading numbers in an unfamiliar form and counting confidently through zero are early steps towards the integers and temperatures that children rely on right through secondary maths.
One note on timing. Counting backwards through zero is named in the Year 4 programme of study, but most schools follow a scheme that holds negative numbers back to Year 5, where they get a proper block of teaching: what a negative number is, counting through zero, comparing and ordering, and finding the difference. So this page explains negative numbers for Year 4, and the quizzes for them sit in Year 5 alongside the rest of that work.
What is in this topic
- Read Roman numerals from I to C, the values one to one hundred
- Match Roman numerals to ordinary numbers and back again
- Understand how the count carries on below zero into negative numbers
- See why minus 5 sits below minus 2, ready for the Year 5 practice
How to help at home
Both halves of this topic reward short, frequent practice woven into everyday moments rather than one long sitting. A couple of minutes spotting Roman numerals on a clock face or reading a cold-day forecast does far more than a worksheet at the weekend.
- Point out Roman numerals where they already appear, then read them together: a clock showing XII at the top and IX for nine, or the date at the end of an old film. Ask 'what ordinary number is that?' and then the reverse, 'how would we write 24 in Roman letters?' (XXIV).
- Build the building blocks first so the rest follows. Make sure I (1), V (5), X (10), L (50) and C (100) are rock solid, then larger numbers are just those added up left to right: LXX is 50 and 10 and 10, which is 70.
- Practise counting backwards through zero out loud using something real, like a temperature dropping: 3, 2, 1, 0, then keep going into minus 1, minus 2, minus 3. Saying zero out loud as you pass it stops it being skipped.
Where children get stuck
The most common Roman numeral slip is adding every letter up even when a small one comes first, so IV gets read as 6 (5 and 1) instead of 4. The fix is to teach the eye to look left: if a smaller letter sits in front of a bigger one, it is taken away, not added. Practise the four that matter at this level, IV is 4, IX is 9, XL is 40 and XC is 90, until they are spotted instantly.
With negative numbers, children often think the count gets bigger going down, so they read minus 5 as warmer than minus 2 because 5 is the bigger number. A number line cures this fast: draw zero in the middle, count left into the negatives, and the further left you go the colder or smaller it is, so minus 5 sits below minus 2.