Education7 min read
Cleopatra Beyond the Legend: Reading Around Hostile Roman Writers
Nearly every story about Cleopatra comes from the side that beat her. What coins, papyri and her enemies' own hesitations actually establish about her.
383 articles · page 9 of 16
Education guides, page 9
Articles 193–216 of 383, newest first. The introduction to this reading list, its topic hubs and the guides other articles cite most are on the first page.
Education articles 193–216
- Education5 min read
The Columbian Exchange: Crops, Animals, Disease and Catastrophe
The Columbian Exchange moved crops, animals and disease across the Atlantic after 1492. What the evidence supports, and why the death toll is still contested.
- Education5 min read
Common History Myths, Corrected — and Why They Stick
Four widespread history myths checked against museum, archive and NASA sources, plus what memory research says about why corrections so often fail to land.
- Education6 min read
Six Reasoning Mistakes That Show Up in Puzzles
Valid but untrue, one rule assumed unique, a conditional read backwards. Six errors that wreck puzzle answers, each with a checkable example and a fix.
- Education6 min read
Comparing Two Fractions Without a Common Denominator
Four ways to decide which fraction is bigger, ranked by cost: benchmark against a half, match numerators, measure distance from one, then cross-multiply.
- Education6 min read
The Compensation Strategy: Round, Operate, Then Undo the Change
Round an awkward number, do the easy sum, then undo the change. The hard part is the undo, and the direction differs between addition and subtraction.
- Education6 min read
If-Then Reasoning and the Two Mistakes Everyone Makes
From 'if P then Q' only two inferences are valid. The four forms, why the invalid pair feels right, the contrapositive, and what 'only if' actually means.
- Education6 min read
Why Some Historical Figures Have Contested Legacies
Four separate questions get tangled in every argument about a contested figure. Separating them makes the disagreement legible instead of merely loud.
- Education5 min read
Counting Up: Subtraction as Making Change
Stop taking away and measure the gap instead. Counting up turns three-digit subtraction into two or three easy hops, and it is how change is made at a till.
- Education6 min read
Vertically and Crosswise: Two-Digit Products in a Single Pass
A digit-by-digit multiplication that produces the answer right to left with running carries, instead of building partial products and adding them at the end.
- Education4 min read
What a Daily Challenge Format Is Good For
How a date-seeded daily challenge works, why everyone gets the same one, what a once-a-day cap is protecting, and where the format stops being useful.
- Education6 min read
Dating North America Before Columbus: Tree Rings, Mounds and Disputed Foundings
Tree rings, stratigraphy and radiocarbon date North America before 1492 — and one revision moved an entire region's chronology by decades. Here is how.
- Education6 min read
Dating Southeast Asian History: Inscriptions, Chronicles and Foreign Records
Southeast Asian chronology rests on Saka-era stelae, court chronicles, foreign envoy reports and radiocarbon — and on knowing what each one can carry.
- Education6 min read
Deductive Reasoning, With Examples You Can Check
A deductive argument promises its conclusion cannot be false if the premises are true. Validity, soundness, the counterexample test, and why belief interferes.
- Education5 min read
Deep Time on a History Timeline: Seven Million Years Before the First City
Written history runs about five thousand years. The human family tree runs about seven million. Here is what fills the gap and how the dates are fixed.
- Education5 min read
Delayed Recall: What a Blank Pause Does to an Answer
A retention interval is the gap between learning something and being asked for it. Why an empty pause is easy, a filled one is brutal, and what follows.
- Education6 min read
Deliberate Practice, Applied to a Five-Minute Drill
Deliberate practice needs a specific target, immediate feedback, difficulty just above your level, and correction. Here is how that maps onto a short drill.
- Education5 min read
Did People Really Think the Earth Was Flat?
Educated people knew the earth was a sphere long before Columbus. Here is the ancient evidence, and where the nineteenth-century flat-earth story came from.
- Education5 min read
Digit Span: What the Number Actually Means
A digit span is the longest run of numbers you can repeat back. How the stepped procedure produces that figure, and why an app's best span is not a test score.
- Education6 min read
Estimating Sales Tax From Friendly Blocks
Sales tax rates are awkward on purpose. Break the rate into blocks — 8.25% is 10% minus 2% plus a quarter of 1% — and the arithmetic becomes two easy steps.
- Education7 min read
Famous Explorers in History, and the Guides Who Got Them There
Most famous voyages depended on navigators, interpreters and guides whose names were left off the record. Who they were, and what the evidence shows.
- Education5 min read
Fibonacci and Other Recursive Sequences
What makes a sequence recursive, how Fibonacci and Lucas numbers differ only in their seeds, and which golden ratio claims actually hold up.
- Education6 min read
Working Out the Original Price From a Sale Price
Reverse a discount by dividing, never by adding the percentage back. Here is why, plus the fraction shortcuts that make the division easy.
- Education6 min read
Finding the Rule: Difference Tables and Second Differences
A mechanical method for finding the rule behind a number pattern when inspection fails, using difference tables, constant rows and degree counting.