Month 2 · Organize data and check calculations
Four relative self-study weeks on references, units, versions and reviewable calculations. Adapt your pace; no live classes, mandatory attendance or guaranteed daily duration. The outcome is one monthly activity M02.
This is the developed Month 2 learning resource, not the entire twelve-month course. The four exercises form one monthly activity M02. Reading, personal marks and self-scores do not verify academic completion.
Complete source F2 — fictional case only
A fictional stationery shop receives SOL02: three N01 notebooks and two L01 pencils. F2 is current only for this exercise. These are teaching figures, not APEX prices or a commercial offer. No orders, accounts or tools are connected.
| Reference | Fictional product | Exercise unit | Unit price COP | Stock on sheet |
|---|---|---|---|---|
| N01 | A5 notebook | Indivisible unit | 8,000 | Unknown |
| L01 | HB pencil | Indivisible unit | 1,200 | 12 in case |
| C01 | Folder | Indivisible unit | 2,500 | 4 in case |
Historical F0 listed N01 at COP 9000; do not use it for SOL02. Transport, discounts, taxes and sale terms are unspecified: do not calculate a real charge. Quantities in this exercise are positive integers and prices use whole COP.
Week 1 · Define columns, units and sources
Goal: Prepare a table another person can interpret and check.
A number alone does not explain its meaning. Define reference, quantity, unit, unit price, subtotal and source before organizing data. Reference identifies the product; quantity counts units; unit price belongs to one unit. Subtotal depends on both. Numeric columns are not interchangeable simply because they look similar.
Version is evidence. F0 and F2 are not prices to average: this case specifies which is current. Preserve the original and use a working copy identifying F2. Record what changed and why; do not rely on memory or a generic file name such as “final”. Another person needs the same source to reproduce your decision.
This exercise needs fictional codes, quantities, prices and pending checks. It needs no names, telephone numbers, identity documents, passwords or addresses. Do not copy customer files to make it realistic. A complete invented source allows reasoning to be checked without exposing other people. Distinguishing necessary from available information is part of the design.
Case for review
One list says “N01 | 3 | 8000” with no headers. Another says “Notebook | 9000 | F0”. A reader cannot tell whether 8000 is unit price or subtotal, or whether F0 may be used.
Your activity
Define fields and units in worksheet 1. Convert SOL02 into two rows with references and source F2. Leave subtotals for next week. Add an awaiting-review state and list information not to collect.
Worked feedback — compare after trying
N01: quantity 3, indivisible unit, COP 8000 unit price, source F2. L01: quantity 2, COP 1200 unit price, source F2. 8000 is not a three-notebook subtotal. F0 is historical and not the SOL02 source. No personal data is needed.
Supporting artifact 1: field dictionary, normalized rows and version.
Week 2 · Keep operations and check subtotals
Goal: Calculate reproducibly and distinguish products from a final charge.
Write the operation before the result. Each row multiplies quantity by unit price; then sum the requested product rows. Someone else must be able to reproduce it without trusting a final number or the fact a spreadsheet or AI wrote it. A correct formula using the wrong source price is still wrong for this case.
English display uses COP 8,000 for eight thousand COP. CSVs use 8000 without separators to reduce ambiguity. This is a teaching convention, not a payment-processing specification. Worksheets contain no formulas. Hand calculation with written steps is acceptable; the important point is reviewable inputs and reasoning.
A product subtotal does not automatically include transport, discounts or missing terms. Do not turn unknown into zero to obtain a complete-looking figure. Availability cannot be inferred from arithmetic either. Keep the remaining unknowns beside the result and explain what review would be needed before real use.
Case for review
For SOL02, a draft takes N01 at 9000 from F0 and calculates COP 29400. A separate variant asks for two N01 and five L01 using F2.
Your activity
Calculate both SOL02 rows and their sum. Explain the draft error and solve the variant separately. Distinguish product subtotal from final price or confirmed order in a sentence.
Worked feedback — compare after trying
SOL02:3×8000=24000;2×1200=2400;products=COP 26400. The draft mixed F0:27000+2400=29400, a 3000 difference. Variant:2×8000+5×1200=COP 22000. Transport and N01 stock remain unknown; no order is confirmed.
Supporting artifact 2: two separate scenarios, operations and result limits.
Week 3 · Find errors and design exception paths
Goal: Check data types, references and consistency before automation.
An orderly table may still contain errors. Check each quantity against the case rule, each reference against F2 and each subtotal against its operation. Do not convert ambiguity into a number for convenience. “Two and a half” does not fit an indivisible unit; clarification is better than unauthorized rounding.
Separate a known error from missing information. If F2 supplies the correct value for a known reference, correct it with that source. If X01 is absent, do not choose a similar product or zero price. Identify the missing source a person would need. An absent sheet does not authorize inventing one.
Before connecting automation, exceptions need an outcome and owner. Here you simulate them on paper: valid for calculation, correct using source, or pending clarification. Preserve input, correction and reason for later review. Nothing in this exercise sends messages, updates inventory, reserves products or confirms delivery.
Case for review
Four independent tests: A puts “3 notebooks” in a numeric quantity field; B calculates two pencils at1200 as24000; C asks for X01 without a sheet; D requests two and a half notebooks despite indivisible units.
Your activity
For each test record input, rule, expected output, correction or unknown, and evidence. Preserve original text. Use no real customers or connected tools.
Worked feedback — compare after trying
A: separate quantity 3 and N01 when supported by the inquiry, noting the change. B:2×1200=2400, not 24000. C: reference and price pending; do not invent them. D: ask rather than round. Passing an arithmetic check does not confirm stock or charging.
Supporting artifact 3: four tests with source, decisions and traceable corrections.
Week 4 · Document changes and assemble M02
Goal: Prepare one monthly activity with evidence and reasoned self-review.
M02 combines the field dictionary/table, operations, tests and change note. Preserve initial and corrected data with source and reason. An index and clear sections suffice if another person can reconstruct the work; many identical copies are unnecessary. Four weeks support one monthly activity and do not change the approved annual count.
Approved rubric v1 has four criteria scored0–2: facts/sources, artifact/process, data/human review and reasoning/limits. It requires minimum 6/8 with no zero and human review. Therefore2+2+2+0=6 fails the rule. Twelve personal checkmarks likewise cannot replace twelve actual reviewed artifacts and a portfolio.
Self-review helps correction, not invented approval. Give evidence, reasoning and an improvement per criterion. An authorized person must review actual work when formal submission is available. This page receives no uploads, gives no human grade and issues no statements or benefits. A local result only helps preparation.
Case for review
One package claims “verified total” without operations or version. Another retains F2, both scenarios and four tests, but fails to explain why stock and transport are still unknown.
Your activity
Assemble one M02 package with the three artifacts, change log and rubric. Explain in five sentences what was corrected, which source supports it and what remains unknown. Keep it locally.
Worked feedback — compare after trying
The first package needs operations and F2; it is not reproducible. The second needs limits: 26400 is not a final charge. A self-score2+2+1+1=6 with no zero is not approval; human review remains pending. Evidence must show reasoning, not only a sum.
Monthly activity M02: table, operations, tests, changes and rubric in one package.
Assemble your single monthly package
Download M02 package guide (TXT)
Keep your work locally. Formal review requires actual artifacts and an authorized human reviewer. No certificate, enrollment or benefit is issued by this page. The other eleven months and final portfolio remain separate parts of the annual program.
Optional AI tutor — read consent and limits first · My personal study marks, not academic verification