Free printable · 8 puzzles · answer key

For kids who finish early.
Print these puzzles.

For teachers and parents of fast finishers: number bridge puzzles that turn adding into real logic.

Puzzle 0 · try it here0 flips · par 2

0of 3 islands balanced

Tap a bridge to swap its two numbers. Watch both island counters change.

Get the free PDFDownload Number Puzzles: Sumbriska on the App StoreFree on iPhone

What makes a good early finisher math puzzle?

A good early finisher puzzle uses facts the child already knows, takes five to ten quiet minutes, checks itself, and has exactly one answer. Bridge puzzles fit: the sums stay within 20, but every bridge is a choice, and one wrong choice shows up on two islands at once.

Most early finisher packs we looked at are colouring-heavy or locked behind a store checkout. This one is a plain four-page PDF: a rule card with a worked example, two pages of puzzles that grow from three islands to six, and an answer key you can fold back before copying.

Eight puzzles, one rule, no sign-up.

How bridge puzzles work for early finishers, in 3 steps

  1. Read the targets. The number inside each island is what it needs. Look for the island with the fewest bridges first.
  2. Choose a way round. Every bridge holds two numbers. One goes to each end. Write the number each island gets in the little box beside it.
  3. Check every island. Add the boxes around each island. If one is off, a bridge near it is the wrong way round. Swap and re-add.

The checking is the maths: every swap means re-adding two islands.

A mini story: the ten minutes after the test

Picture a Year 3 or second-grade room on a Thursday. The quiz is out, and two children are done in twelve minutes. They get page 2. The first puzzle has three islands, so it is done in two. The fourth has a bridge holding 8 and 4 that keeps going the wrong way, and suddenly they are arguing, quietly, about which island should get the 8.

That argument is the point. Nobody needed a new worksheet explained, nobody needed a device, and the answer key stayed folded on the teacher's desk.

An illustration of how we picture the pack being used, not a report from a real classroom.

Where the app fits, honestly

We make Sumbriska, the iPhone app these puzzles come from. On a phone, you flip a bridge with a tap and both totals change instantly, so the checking is done for you. That is great at home and not what a classroom needs, which is why the printable exists.

One design decision we made: hints, Undo and step explanations in the app never cost XP. We wanted a stuck child to ask for help without losing anything.

Who should pick something else: if your early finishers need times-table practice or work with fractions, these will feel too easy on the numbers. A fact-fluency game or a fraction puzzle pack fits better.

Early finisher puzzle questions

What should early finishers do in math class?

Something that stretches the same skill without becoming extra homework: a short logic puzzle that uses the facts they already know. Bridge puzzles use addition within 20, but the real work is reasoning about which way round each bridge goes.

What age are these bridge puzzles for?

Most 7 to 11 year olds who are fluent with addition within 20. Puzzles 1 and 2 are gentle enough for a confident 7 year old; puzzles 7 and 8 make adults pause.

Is there an answer key?

Yes, page 4 of the PDF has all eight solutions. Each puzzle was checked by a short program that tries every way round for every bridge, and each has exactly one answer.

Do I need to sign up or give an email to download it?

No. It is a direct PDF download, free to print and copy for your class or your kitchen table.

Is Sumbriska, the app, free?

The free download includes regions 1 and 2, the Daily board, The Deep and Harbor Run. An optional Voyage Pass ($4.99 a month or $29.99 a year, no free trial) adds regions 3 to 6, all side boards, Gale Run and premium cosmetics. There are no ads.

Can a child use the app on their own?

Child profiles in Sumbriska have no purchases and no links, and the adult area is protected by a PIN or Face ID. It works fully offline and the listing says no data is collected.

The same idea on iPhone

Store screenshots, toned to match this page. Marker notes are ours.

Sumbriska practice board: islands with targets 12, 16 and 26 joined by numbered bridges target
A practice board: the tags show what each island has now.
Two Tides board where one bridge layout must meet high tide and low tide targets two sets of targets
Two Tides: one arrangement has to satisfy two schedules.
Difficulty picker with Gentle, Steady, Clever and Deep and the Logic Lens hint panel start at Gentle
Gentle to Deep, with free hints in the Logic Lens.

Print tonight, play tomorrow

The PDF is free with no sign-up. If a child asks for more, Sumbriska has two free regions and a new Daily board every day.

Get the free PDF

Download Number Puzzles: Sumbriska on the App Store

Download free on the App Store

Updated November 2026

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