Friday, September 25 — Day 22
The three leaks. Yesterday was the map of the whole trial. Today is only the places the points kept falling out.
The clock
Same as yesterday. 2 hours 30 minutes of work, a 20-minute break after every 40.
- 9:30–10:10 — valence, on paper. Don't count across the row. Read the group.
- 10:10–10:30 — no phone.
- 10:30–11:10 — two-digit multiplication. The method is right. The last addition is where it slips. Write all four pieces before you add.
- 11:10–11:30 — no phone.
- 11:30–12:10 — two dates out loud: Westphalia 1648, Versailles 1919. Then one fraction that doesn't come out obvious, reduced at the end.
- 12:10–12:30 — no phone.
- 12:30–13:00 — exam. 18 questions. A and B share nothing.
Phones off until 13:30.
Valence, the short version
Outer electrons. Group tells you the number.
- Group 1 (H, Li, Na) = 1
- Group 2 (He is the exception: 2, not 8; Be, Mg = 2)
- Then across the row: B 3, C 4, N 5, O 6, F 7, Ne 8
- Same pattern on row 3: Al 3, Si 4, P 5, S 6, Cl 7, Ar 8
Sodium (1) gives an electron to chlorine (7). That's table salt. You don't need more than that today.
The multiply, one worked one
17 × 25.
Split: (10 + 7) × (20 + 5).
Four pieces: 10×20 = 200, 10×5 = 50, 7×20 = 140, 7×5 = 35.
Add them in that order: 200 + 50 = 250, + 140 = 390, + 35 = 425.
Write the four numbers down. The slip is almost always the last add, not the idea.
The two dates
- Westphalia, 1648. Often called the start of the idea that a country rules its own land.
- Versailles, 1919. Signed in the Hall of Mirrors. The terms were so hard that historians point at them as a cause of the next world war.
If you remember nothing else from the peace list today, remember those two years.
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