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Explore whole numbers from 2 to 20 as two parts. Adjust or swap the parts and connect the diagram, counters, and addition and subtraction facts.
Current mission
6 + 4 = 10
Overview
Understand what the tool solves, how it works, and the boundaries of its data.
A number bond shows a whole as the sum of two parts. If the whole is 10 and one part is 6, the other part is 10 − 6 = 4, so 6 + 4 = 10. Swapping the two parts keeps the same whole: 4 + 6 = 10. The reverse subtraction facts also follow: 10 − 6 = 4 and 10 − 4 = 6.
This visualizer lets you explore whole numbers from 2 through 20. One part can range from 0 to the whole; the other is calculated as whole minus the selected part. The diagram, counters, and four equations update together. Colors distinguish the two parts; they do not mark right and wrong.
Explore mode shows a chosen bond directly. Challenge mode presents a target-part equation with an unknown part, such as 6 + ? = 10, so learners can reason about the missing amount before checking the relationship.
Guide
Follow the workflow and verify inputs and outputs with practical examples.
Start in Explore and read the whole and first part. The other part is the difference.
Change the whole, then adjust the first part from zero up to that whole. Watch the diagram and equations change.
Use the swap control to reverse the two parts. Compare both addition equations and subtraction facts.
Choose Challenge to get a missing-part prompt. Adjust the first part until it matches the target in the prompt.
Use Random for another challenge, or Reset to set the first part to half the current whole, rounded down.
Example: set the whole to 8 and the first part to 3. The second part becomes 5, giving 3 + 5 = 8 and 8 − 3 = 5. Change the first part to 4 and the second becomes 4.
Use cases
See how the tool fits into real work and everyday tasks.
Set a whole such as 12, ask students to predict the missing part, and adjust the first part to compare their prediction.
A caregiver can name a whole and one part, then ask the learner to explain how subtraction finds the rest.
Sketch two groups of counters on paper, then read both addition orders and the matching subtraction facts.
For example, pair eight counters as three and five. The display helps show that changing one part while holding the whole fixed changes the complement.
Q&A
Find concise answers to common questions and confusing cases.
No. It displays one pair at a time. Adjust the first part in Explore to inspect other pairs, or use a challenge for a missing part.
Yes in Explore, where the first-part control runs from 0 through the selected whole. These boundary cases show 0 + whole and whole + 0.
Challenges choose a whole from 5 through 20 and a nonzero target part smaller than that whole. Explore uses totals 2 through 20 and includes the boundary parts.
Notes
Review scope, result limitations, and important precautions before use.
The display shows one bond at a time; it is not a saved list of all combinations for a whole. Challenge mode also does not test zero and whole-sized boundary parts. Use paper, counters, or another practice format when you need a complete inventory or a record of independent work.
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