How to play Rainbow to 10
Rainbow to 10 lays the digits 0 to 10 out in one long row and asks the same question over and over: which two of these make 10? Tap a number, then tap its partner. If the two add to 10, a thick coloured arc springs across the row to join them and both digits dim so they cannot be used twice. Six arcs, one for each pair, complete the rainbow.
The colours are not decoration. Every pair keeps its own place in the spectrum, so 0 and 10 always paint the widest red arc on the outside, 1 and 9 sit just inside it in orange, and the pairs narrow through yellow, green and blue to a violet loop over the 5. After a few rainbows children start calling the colour before they have finished counting, which is the first sign a pair is being remembered rather than worked out.
Nothing is scored and nothing is timed. A pair that does not make 10 shows its actual sum and keeps the first number selected so the player can choose a different partner. There is no penalty and no way to lose a rainbow.
Controls
- Touch or mouse: tap a number, then tap the one that goes with it. Tapping the same number again deselects it, so a mis-tap costs nothing.
- Keyboard: Tab steps through the numbers still in play and Enter or Space picks whichever one has focus, so a child working by keyboard or switch access can finish a whole rainbow.
- The 5: 5 is its own partner, so tap it twice to close 5 and 5. That pair draws as a loop hovering above the row rather than an arc across it.
Every pair that makes 10
There are six: 0 and 10, 1 and 9, 2 and 8, 3 and 7, 4 and 6, and 5 with itself. Knowing all six by heart is a Year 1 objective in the UK National Curriculum, and it is the fact family the rest of primary arithmetic leans on hardest. Bridging through ten, taking away from a teen number and, later, seeing that 30 and 70 make 100 all start with these six.
Drawing them as arcs over a single number line makes the symmetry visible. The arcs nest inside one another, widest at the ends and tightest in the middle, so a child can see that the pairs are not six unrelated facts but one pattern walking inwards from both ends of the row at the same time.
Turning the partner glow off
Glow the partner is switched on in the menu by default. With it on, choosing a number immediately rings its partner in a dashed green circle on the diagram and a dashed green button in the number bank. This points to the matching number while the player practises noticing each pair. Other numbers remain selectable.
Switching the glow off is the difficulty step. Nothing else changes - same six pairs, same untimed board - but the partner now has to come from memory. Playing with the glow on until a child predicts the arc before it appears, then turning it off, offers practice with and without a visual cue. A completed rainbow is not a formal assessment.
The second option, Say the stem sentence, is off by default. Switched on, a correct pair is spoken back as "four and six makes ten", and a pair that misses is read out with its real total followed by "try again" - often the more useful of the two for a child who is guessing.
Stickers
Finishing a rainbow adds to the site-wide sticker book. The first completed rainbow unlocks First Arc, five unlock Rainbow Maker and fifteen unlock Rainbow Pro. The running total is kept in the browser, so it carries across sessions on the same device without an account.
Completing a rainbow also awards Bonds to 10 from the shared Number Bonds set, the cross-game sticker for completing practice in one bond family. Because a full rainbow is all six pairs in one sitting, Rainbow to 10 hands that sticker over outright instead of counting up single correct answers the way Part-Whole Pop and Missing Number do.
Questions parents and tutors ask
What are number bonds to 10?
Number bonds to 10 are the pairs of whole numbers that add up to 10. There are six of them: 0 and 10, 1 and 9, 2 and 8, 3 and 7, 4 and 6, and 5 with itself. Knowing all six by heart is a Year 1 objective in the UK National Curriculum.
How many rainbow arcs are there?
Six, one per pair. Each pair keeps a fixed colour, so 0 and 10 always paint the widest red arc on the outside and 5 with itself always paints the violet loop in the middle.
Can a child get an answer wrong?
A pair that does not make 10 shows its actual sum. The first number stays selected so the player can try a different partner. There is no score penalty, no timer and no way to lose a rainbow.
Is Rainbow to 10 free?
Yes. It is free to play with no signup, no download and no in-game purchases. Optional analytics follows your cookie choice.
Does it work on a tablet or an interactive whiteboard?
The rainbow diagram scales with the screen. Separate number buttons wrap into rows on smaller screens and support touch, mouse and keyboard. A classroom whiteboard can show the same page, including over a screen share.
Who Rainbow to 10 is for
Rainbow to 10 was built by a UK SEND tutor with QTS for children who need bonds to 10 to become automatic. It suits Reception and Year 1 children meeting the pairs for the first time, and it works just as well as a two-minute warm-up further up the school for a child whose arithmetic is slow because the bonds are still being counted out on fingers.
The design choices are deliberate for anxious and neurodivergent learners: no clock, no lives and no streak to break. A wrong pair keeps the first number selected and shows the sum, so the player can try another partner. The optional partner hint supports guided practice; completing the rainbow is an activity reward, not an assessment of mastery.