Reading the adjacent cell
The most common table mistake isn't arithmetic at all — it's pulling the number from the row above, the column beside, or a similarly named header, then computing perfectly with the wrong data.
Why your brain does this
Dense tables with similar headers (Q3/Q4, 2023/2024, Revenue/Profit) overload visual tracking, especially under time pressure. Your eyes jump a row without your awareness — the calculation then feels confident because the maths IS right.
The fix
Anchor with two fingers (or the cursor): one on the row label, one on the column header, and read where they cross. On screen, use the row's distinctive value as a checksum — if the number you grabbed doesn't sit beside its neighbours as expected, re-anchor.
See the trap in a real question
| Warehouse | Q1 | Q2 | Q3 | Q4 |
|---|---|---|---|---|
| North Grid | 105 | 115 | 155 | 110 |
| Highland | 130 | 190 | 110 | 80 |
| Eastern Plain | 120 | 185 | 125 | 100 |
How many units did the Highland warehouse ship in Q4?
Locate the exact row and column named in the question and read the single cell where they meet. The correct answer is 80. Traps to avoid: 190 comes from the "adjacent cell" error; 100 comes from the "adjacent cell" error; 110 comes from the "adjacent cell" error; 130 comes from the "adjacent cell" error.
Where it strikes
This trap appears in 32 of our questions, across: Table lookup · Difference.
Do you make this mistake?
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