Number Bonds

Number bonds are pairs of numbers that add up to a given total. The concept comes from Singapore Math, where educators found that showing children how a whole splits into two parts builds strong number sense. A 2009 study by Siegler and Ramani in Developmental Psychology proved that playing number games improves early arithmetic skills in young children. Our game lets kids practice bonds to 10, 20, and 100 through a visual circle diagram. Pick a difficulty and start playing now.

1. Choose a difficulty: Easy (bonds to 10), Medium (bonds to 20), or Hard (bonds to 100).
2. Select a mode: Timed Challenge for a 60-second sprint, Practice for relaxed learning, or Story of Numbers to see all bonds for a single target.
3. Look at the number bond diagram. A large circle at the top shows the whole. Two smaller circles at the bottom show the parts. One circle is blank.
4. Figure out the missing number. If the whole and one part are shown, subtract the part from the whole. If both parts are shown, add them together.
5. In Easy and Medium, tap one of the four answer buttons. In Hard, use the on-screen numpad to type your answer, then press the check button.
6. Correct answers add points to your score. A streak of three or more correct answers in a row triggers a score multiplier.
7. In Timed mode, answer as many as you can before the clock runs out. In Practice mode, there is no timer. Just keep going.

• A number bond has three values: the whole and two parts. The two parts always add up to the whole.
• Each round shows two of the three values. You must find the missing one.
• Easy mode uses target numbers up to 10 and gives four multiple-choice options.
• Medium mode uses target numbers up to 20 and gives four multiple-choice options.
• Hard mode uses target numbers up to 100 and requires typed input via the on-screen numpad.
• In Timed Challenge mode, you have 60 seconds. The timer turns red and pulses in the final 10 seconds.
• In Practice mode, wrong answers do not break your streak. The game simply shows the correct answer and moves on.
• In Story of Numbers mode, the game displays every pair of parts that add up to your chosen target number.

• Memorize the bonds to 10 first. There are only five unique pairs: 1+9, 2+8, 3+7, 4+6, and 5+5. Knowing these by heart makes every harder level faster.
• Use doubles as anchors. If you know that 6+6=12, then 6+7=13 is just one more. Doubles are the easiest bonds to recall under time pressure.
• When finding a missing part, subtract. If the whole is 20 and one part is 8, think 20 minus 8 equals 12. Subtraction is faster than guessing.
• When finding a missing whole, add the two parts. Train yourself to look at both parts and say the sum out loud before checking the options.
• In Hard mode, break large numbers into tens and ones. To find a part of 100 when the other part is 47, think 100 minus 40 equals 60, then 60 minus 7 equals 53. Chunking saves time.

• Bonds to 10: The foundation level. Children learn the five pairs that make 10. This is the first set taught in Year 1 of the UK National Curriculum.
• Bonds to 20: Builds on bonds to 10. Children apply the same part-whole logic to larger numbers, typically in Year 2.
• Bonds to 100: Advanced level for Years 3 and 4. Children work with tens and ones, often using chunking strategies to subtract from 100.
• Story of Numbers: A reference mode that lists every pair of parts for a chosen target. Great for visual learners who want to see all bonds at once.

• Number bonds give children a visual way to understand addition and subtraction. The circle diagram makes the part-whole relationship obvious.
• Parents and teachers search for number bonds games directly because the term appears in the UK National Curriculum and Singapore Math textbooks.
• The game adapts to different ages. A 5-year-old can start with bonds to 10 while a 9-year-old challenges themselves with bonds to 100.
• Practice mode removes all pressure. Children can learn at their own pace without a timer or penalties for wrong answers.
• The streak system rewards consistency. Kids love seeing their multiplier grow as they string together correct answers.

Play Number Bonds free in your browser. No downloads, no accounts. The game works on desktop, tablet, and phone with full touch support. The on-screen numpad prevents the mobile keyboard from shifting the layout. Start practicing now.

Number Bonds turns a core early math skill into a visual, interactive game. Children see how numbers split and combine. They practice at their own pace or race the clock. Pick a level, pick a mode, and start building number sense today.

• UK National Curriculum: Mathematics programmes of study (KS1 and KS2)
• Siegler & Ramani (2009) - Playing linear number board games promotes young children's number sense, Developmental Psychology