THE NUMBERS, EXPLAINED
How to use this calculator.
All sessions have equal weight. Round the target attended count up to a whole session. A required count above the remaining sessions is reported as unattainable, with zero permitted absences.
Start with your inputs
Enter sessions held, sessions attended, sessions remaining, required attendance (%). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Sessions held | 20 |
| Sessions attended | 15 |
| Sessions remaining | 10 |
| Required attendance (%) | 80 |
A worked example
With the example inputs above, future sessions required is 9. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Future sessions required | 9 |
| Permitted future absences | 1 |
| Maximum final attendance (%) | 83.333333 |
| Feasibility | Target remains attainable |
How this is calculated
Future sessions required
max(0, roundUp((a+c) × d/100) − b).
Permitted future absences
max(0, c − future sessions required). Check feasibility separately.
Maximum final attendance (%)
(b+c)/(a+c) × 100.
Feasibility
The target is attainable if future sessions required ≤ c.
Symbols and units
- a
- Sessions held
- b
- Sessions attended
- c
- Sessions remaining
- d
- Required attendance (%)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions and limits
All sessions have equal weight. Round the target attended count up to a whole session. A required count above the remaining sessions is reported as unattainable, with zero permitted absences.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Future sessions required; Permitted future absences; Maximum final attendance (%); Feasibility. The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: All sessions have equal weight. Round the target attended count up to a whole session. A required count above the remaining sessions is reported as unattainable, with zero permitted absences.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
OpenStax: algebra and proportional reasoning ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
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