A yo-yo practice log needs a named denominator

A yo-yo practice log can produce three different percentages from the same ten planned slots. Five successes among eight attempts is 62.5 percent. Eight attempts among ten planned slots is 80 percent. Five successes among ten planned slots is 50 percent. The arithmetic can be correct in every line while a heading makes one of those figures misleading.

The log below is wholly invented. Its slots, outcomes and later revision demonstrate record checking, without a physical trial of either linked product. Nothing here defines a trick, teaches a throw or return, sets a practice schedule or predicts what a player will achieve. The task is to diagnose what a recorded percentage actually counts.

Keep the original slot record beside the summary

Our fictional player, Ren, has a paper plan with ten numbered slots. The original record marks slots 1, 2, 4, 7 and 9 as successful. Slots 3, 6 and 8 are marked unsuccessful. Slots 5 and 10 are explicitly marked not attempted. These ten assignments are the entire data set for the first example.

Successful and unsuccessful are labels already supplied by this fictional record. We do not infer them from equipment, photographs or an imagined movement. A real log would need its own stated outcome criterion before those labels could support a comparable summary. This guide supplies no physical performance standard for a yo-yo activity.

Copy the three groups onto the checking sheet before calculating. There are five successes, three failures and two unattempted slots. Their counts add to ten, and every slot appears exactly once. This partition check catches a different kind of problem from an incorrect division: a duplicated or missing slot would change the underlying record.

Keep the original marked page available while reviewing a summary. If someone has typed ten rows into another table, compare the identifiers as well as the total. Ten copied entries could include one slot twice and omit another. A matching row count alone would not establish that the same ten assignments were preserved.

Calculate the attempt success rate from the attempted group

Under our declared labels, an attempt is either successful or unsuccessful. The five successful and three unsuccessful slots therefore give eight attempts. Divide the five successes by those eight attempts. Five divided by eight is 0.625, or 62.5 percent. This is the attempt success rate for the original invented record.

The two slots explicitly marked not attempted do not belong in that denominator. Nor do they become failures merely because they lacked a success mark. The recorded distinction already tells us they were not attempted. Preserve it when explaining why eight, rather than ten, appears beneath the five successes.

The figure does not state that Ren succeeded in 62.5 percent of the planned slots. That would substitute the full plan for the attempted group. It also does not describe a product’s reliability or the probability of a future success. It is a proportion calculated from the eight declared outcomes in one fictional record.

Write the count pair beside the percentage: five successes out of eight attempts. Another reader can then inspect the underlying group without reverse-engineering a decimal. If the heading says only “success,” add the question the number answers before treating it as a complete summary.

Give unattempted practice slots their own status

A completion question uses a different count pair. Eight of the ten planned slots were attempted, so the completion proportion is eight divided by ten, or 80 percent. The two unattempted practice slots explain the remaining 20 percent of this plan. Neither group supplies an extra success or failure outcome.

A third question asks how many planned slots ended in a recorded success. Five of ten did, giving 50 percent. That statement can coexist with the 62.5 percent figure because their denominators are different. Keep the explicit phrase “of planned slots” beside the 50 percent result.

Suppose Ren’s summary heading says “Successful attempts: 50 percent,” but the calculation beneath it is five divided by ten. The diagnosis is a denominator-label mismatch. The calculation used all planned slots while the heading named attempts. Correct the heading or calculate five divided by eight, depending on which question Ren meant to report.

Do not fix that mismatch by changing the two unattempted entries to failures. That would alter the supplied observations to fit the summary. The original record distinguishes eight attempts from ten plans. A corrected summary should preserve that distinction and say which count pair it uses.

Separate an unknown outcome from a known non-attempt

Now create a revised version of the log. Ren establishes that slot 5 was attempted, but its outcome was not recorded. Keep all eight original known outcomes unchanged, and keep slot 10 explicitly not attempted. The revised record has nine confirmed attempts, eight known outcomes and one unknown outcome.

The unknown entry cannot be classified as a success or failure from silence. It also cannot remain in the not-attempted group after the revision establishes that an attempt occurred. Write both fields clearly: attempt confirmed, outcome unknown. These fields concern different facts within the invented example.

There are exactly two possible completions of that missing binary outcome under our stated model. If slot 5 was unsuccessful, the revised nine attempts contain five successes, giving five ninths, approximately 55.56 percent. If it was successful, they contain six successes, giving six ninths, or approximately 66.67 percent.

The revised record therefore does not establish one exact success proportion across all nine attempts. Its two permitted completions give the bounds just calculated. Do not select the midpoint, pick the more flattering endpoint or use the original 62.5 percent as though the missing outcome had been resolved.

Five successes among eight known outcomes still equals 62.5 percent. That result now needs the narrower heading “among known outcomes.” It leaves one confirmed attempt outside the outcome calculation, so show the missing entry beside it. A percentage can remain numerically unchanged while its relationship to the complete record changes.

Diagnose the record before comparing two summaries

A colleague looking only at the first summary might say Ren went from eight to nine attempts. That is correct for the revised count. Saying Ren improved or declined would require an outcome the revised record still lacks. Keep the change in confirmed activity separate from a conclusion about successful activity.

Version labels make this distinction easy to hand over. Save the original page with slot 5 marked not attempted, then save the revised page with its confirmed-attempt and unknown-outcome entry. Explain what evidence the fictional revision introduces. The earlier figures remain figures for the earlier version rather than being silently overwritten.

If a later answer establishes slot 5’s outcome, update that row and recompute the count pair for the revised record. Do not manufacture an answer to close the table. If it remains unknown, the summary can state the known counts and the two possible completed proportions without declaring one of them the observed result.

This example deliberately restricts every completed attempt to one of two outcome labels. A different log could permit partial completion, several task types or another classification. Such a record needs its own definitions and complete partition before reusing these calculations. A familiar percentage formula does not supply missing category rules.

Pool the counts before reporting the combined attempts

The original record also lets us inspect a misleading combined summary. Put the first two attempted slots, 1 and 2, in one group. Both were successful, so that group has two successes among two attempts, or 100 percent. The remaining six attempted slots contain three successes and three failures, giving 50 percent.

Taking the ordinary average of 100 percent and 50 percent gives 75 percent. That calculation assigns the two groups equal weight, despite their different attempt counts. It does not give the successful proportion among all eight attempts. The combined count remains two plus three successes divided by two plus six attempts: five eighths, or 62.5 percent.

If a heading promises the average of the two group percentages, 75 percent describes that declared calculation. If it promises the successful proportion across every recorded attempt, use the pooled counts instead. This is another heading-and-denominator check, with no new outcome added to the original page.

Keep the two group sizes in the handover note if someone wants both summaries. A bare pair of percentages would hide the unequal counts that explain their relationship. Do not split or regroup slots simply to produce a preferred headline. Start with the question to be answered and retain the original slot assignments so another reader can follow the calculation.

Keep product descriptions out of the outcome cells

The Yoyorecreation Optima offer identifies a mono-metal yo-yo from the Type Face inspired series. Its fields use Light Blue and Blue, and its three photographs show the blue body from different angles. The account supplies no measured practice outcomes or confirmed included-string inventory here.

The General Yo Legato 2 offer identifies a bi-metal yo-yo with Gold wording while its description retains Rose Gold from the source title. Its three photographs show the pinkish body and contrasting rim. Those appearance and material declarations do not assign a success label to any slot in Ren’s invented log.

Neither selected account establishes how a player performed, how long a session lasted or which real movement counted as successful. The photographs show bodies alone rather than a complete parcel inventory. Keep actual equipment instructions with the actual item; this log check supplies no stringing, adjustment, return or handling procedure.

Hand over the question and the count pair

The watching a yo-yo demonstration guide invites an adult spectator to notice shape and rhythm while the experienced performer retains equipment and handling decisions. That is a social observation, without a scored attempt record. Do not convert a spectator’s remembered impression into one of our invented outcome cells.

The sharing a yo-yo hobby guide follows a fictional beginner asking a partner for a smaller explanation and leaving the next session undecided. It reports no trick result. Enjoying an invitation and recording a successful attempt are separate questions; neither supplies the other’s missing information.

A handover note for the original log can say: ten planned slots, eight attempted, five successful and three unsuccessful, with two explicitly unattempted. Add the requested summary and its count pair. For the revised version, say nine attempts, five known successes, three known failures and one unknown outcome, plus one unattempted planned slot.

A yo-yo practice log is ready for an honest summary when its version, outcome definitions and denominator are visible together. The original ten-slot example supports 62.5 percent among attempts, 80 percent completion and 50 percent successful planned slots. The revised example leaves an outcome unresolved. Preserve that difference rather than forcing every record into one reassuring percentage.