Percentages arrive properly this year, alongside numbers with three decimal places. Here's how it all actually connects.
25 August 2026 · 5 min read
Year 5 is where percentages formally enter the curriculum, and where decimals extend to three decimal places for the first time. Both build directly on the fraction-decimal connection introduced in Year 4 — the difference is that Year 5 asks children to see fractions, decimals and percentages as three interchangeable ways of describing the same underlying amount.
The most important idea in this topic isn't calculating a percentage — it's recognising that a fraction, a decimal and a percentage can all describe exactly the same amount, and being able to move fluently between them. 1/2, 0.5 and 50% aren't three different numbers; they're three different notations for one value. A child who can convert instantly between all three has genuinely understood the connection. A child who can only do it in one direction (say, fraction to percentage, but not the reverse) usually hasn't fully grasped it yet, even if their percentage calculations look fine on paper.
Comparing decimals with different numbers of digits after the point — thinking 0.4 is smaller than 0.25 because 4 looks like a smaller number than 25 — remains a common trap even into Year 5, since it was only introduced with two decimal places in Year 4 and now extends to three. It's worth checking this specifically rather than assuming it's resolved just because a year has passed.
Percentages of an amount (finding 20% of £60) also cause confusion when children try to memorise a separate method for percentages rather than connecting it back to the fraction they already know — 20% is just 1/5, and 1/5 of £60 is £12, using exactly the same fraction-of-an-amount skill from earlier years rather than a brand-new one.
Shopping is genuinely useful here: working out a 10% or 20% discount on a real price connects percentages to something concrete and motivating, and naturally reinforces that 10% means "divide by 10." Money is also a good context for three-decimal-place practice once litres and millilitres or kilograms and grams come up — 1.275 litres is a completely natural, everyday use of three decimal places.
Grasp Maths tests the fraction-decimal-percentage connection in both directions, not just one, so a child who can convert a fraction to a percentage but struggles going the other way gets picked up on that specific gap, rather than being marked as having "got" the topic.
Looking for printable practice too? See our Year 5 maths worksheets, or read the full Year 5 maths overview.
Try a free Grasp Maths practice session, matched to the Year 5 curriculum.