Pocket Puzzle ArcadeUpdated November 2026

The 5-minute game for bonds to 20.

For parents of second graders: launch a number into the beast and make exactly 20.

Two ten-frames: yellow is the beast, orange is your launch.

The beast shows 12. It needs 8 to make 20.

Tap a number to launch it. Say the sum out loud first.

Download on the App StoreFree on iPhone

By the Honest Little Apps studio · Updated November 2026 · We make Number Beasts, so we tell you where it fits and where it doesn't.

What did your launches show?

Every bond above lights one of the nine pairs that make 20 with a one-digit number. Collect them all and your child has said every "teen plus something" fact out loud. The yellow and orange dots are doing the real teaching: 12 + 8 is one full ten, then 2 and 8 making the second ten.

0 of 9 pairs found. Launches 0 · Bonds 0 · Feeds 0 · Bridges 0

Play a few launches above and this note will suggest what to practise next.

BONDFEEDBRIDGE

Those three words are the rules of Number Beasts, cut down for this page. Make exactly 20 and the beast pops (bond). Fall short and it grows, so now it needs a smaller number (feed). Overshoot and it pops, but the leftover spills back in as a brand-new beast (bridge). In the app the target is usually 10; in its third world, Chaos Laboratory, some beasts need 15 or 20.

A bond to 20 is a bond to 10 wearing a coat: 13 + 7 is 10, plus 3 + 7.

Number bonds to 20: the questions parents ask

We grouped the answers in the order they usually come up: before your child starts, while you are playing, and after a week of short games.

Before you play

What are number bonds to 20?
Number bonds to 20 are the pairs of whole numbers that add up to exactly 20: 0 + 20, 1 + 19, 2 + 18 and so on up to 10 + 10. People also use the phrase for all addition facts within 20, such as 8 + 5 = 13. Both meanings matter in second grade, and the same game practises both.
What grade learns number bonds to 20?
In the US Common Core standards, first grade adds and subtracts within 20 (standard 1.OA.C.6), and standard 2.OA.B.2 says that by the end of grade 2 children should "know from memory all sums of two one-digit numbers". England's national curriculum asks Year 1 to use number bonds within 20 and Year 2 to recall facts to 20 fluently.
Should my child know number bonds to 10 first?
Yes. Bonds to 20 are built on bonds to 10. If 7 + 3 still needs fingers, 17 + 3 will too. A quick check: say a number from 1 to 9 and ask for its partner to make 10. Quick, confident answers mean you are ready for 20. If not, spend a week on ten first; our guide on teaching number bonds to 10 has a step checklist.

While you play

What are good number bonds to 20 games with no prep?
Three that need almost nothing: Make-20 Snap, where you write 1 to 9 on some paper slips and 11 to 19 on others, turn two over at a time and snap any pair that makes 20; Coin Frames, where two egg boxes cut to ten cups each hold coins and you ask how many empty cups are left; and Beast on Paper, where you write a number in a circle and your child says what makes it 20.
How do number bonds to 10 help with bonds to 20?
Every bond to 20 with a teen number hides a bond to 10. For 14 + 6, the 4 and 6 make ten, and the ten in 14 makes the other ten. Making ten first is one of the strategies Common Core lists for adding within 20. The two ten-frames in our demo show that split on every launch.
Are timed math fact games a good idea?
Used lightly, yes. The Institute of Education Sciences' 2021 practice guide for struggling math students recommends regularly including timed activities "as one way to build fluency", and rates the evidence strong. Keep the clock friendly: race your own last score, not a sibling. If your child freezes under time, switch to an untimed puzzle game for a while.
My child still counts on fingers. Is that a problem?
Not at the start. Counting on is the first strategy the standards list. The goal by the end of second grade is to move from counting to knowing: making ten, using doubles like 9 + 9, and recalling the fact. A good sign is when your child says "that's 10 and 3 more" instead of counting up from 8.

After a week

How long should number bond practice last?
Short and often works best in our experience: about five minutes, most days, ending while your child still wants one more round. We are a small studio, not researchers, so treat that as practical advice. The point is many short, calm repetitions rather than one long session that ends in tears.
How do I know my child is fluent with facts to 20?
Look for three signs: the answer comes without counting, it comes quickly, and your child can explain it, for example "16 + 4 is 20 because 6 and 4 make ten". If one fact is always slow, put it on a sticky note on the fridge for a week and use it in a game every day.
Does Number Beasts teach number bonds to 20?
Partly, and we want to be exact. Most Bond Lab stages use make-10 beasts. Facts to 20 show up when a number overshoots and the leftover carries on, and in the Chaos Laboratory world, where some beasts need 15 or 20. The real-time arcade mode has a Bond Map that tracks every number bond your child plays.
Is Number Beasts free and safe for kids?
The App Store listing says Number Beasts has no ads, no accounts, no tracking and no in-app purchases. Everything is stored on the device and the whole game works offline. It is rated 4+.

Ten first, then twenty, then speed. Skipping a step is what makes facts feel hard.

Which number bonds to 20 game fits your evening?

Here are three ways to practise, side by side. Two are free and screen-free; one is our app. Pick by how much time and energy you have tonight.

GameYou needWhat it practisesBest for
Coin Frames20 coins, two egg boxes cut to ten cupsSeeing 20 as two tens; the missing partChildren still counting every object
Make-20 Snap18 paper slips: 1–9 and 11–19Fast recall of the nine teen pairsTwo players who like a race
Number Beasts (ours)An iPhone; free, no adsMake-ten planning, carrying leftovers, 15 and 20 beastsA child who enjoys puzzles and wants to do it alone
Number Beasts screenshot: Stage Clear with three stars, solved in one launch with no tools
Three stars for clearing at or under par without help.
Number Beasts Chaos Laboratory screenshot: a splitter halves a number into two shots
Chaos Laboratory: splitters halve a number into two shots.

The app's Daily Lab adds a fresh puzzle every day, made on the device and checked as solvable before your child sees it. Every one of the 45 handcrafted stages is checked by a solver, so none is unwinnable, and each has a par to beat.

Screen-free games build the facts; a puzzle game gives them a reason to be used.

Honest limits

One design decision we stand by: nothing in the game is random. Every stage is a small plan of which number, which order and which angle, so a child who thinks it through always wins. Children who need a teacher's structured intervention, or who are not yet secure with numbers to 10, should start with objects and an adult rather than any app.

Use the app as the treat after the coins, not instead of them.

Number Beasts app icon

Make the perfect bond. Then carry the rest.

45 solver-checked stages, a Daily Lab and a Beast Workshop for building your own boards. No ads, no accounts, no in-app purchases. Open Number Beasts in the App Store.

Download on the App StoreFree on iPhone

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Sources, checked November 2026: Common Core grade 2 operations standards, grade 1 standards, National curriculum in England: mathematics, IES practice guide, Assisting Students Struggling with Mathematics (2021).