1. Left-to-Right Addition
Most people learn to add from right to left on paper. But in your head, left-to-right is far easier because you process the most significant digits first — the ones that give you the rough answer immediately.
This works because you build the answer progressively. At each step you only need to remember one running total. Try starting with two-digit numbers before moving to three digits.
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2. Rounding and Compensating
When one number is close to a round number, round it up, do the easy addition, then subtract the difference. This is especially powerful for numbers ending in 7, 8, or 9.
The key insight: adding a round number is trivial. The only thing you need to track is how much you rounded by. With practice, this becomes one mental step rather than three.
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3. Decomposition
Break one number into parts that are easy to add. This is especially useful when the numbers “complement” each other in a convenient way.
The trick is to find a split that makes the first addition land on a round number. Look for how much the first number needs to reach the next hundred or ten.
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Which technique should I use?
Left-to-right is the most general — it works on any numbers and is the default technique to practice first.
Rounding and compensating is fastest when one number is near a round number (ending in 7, 8, 9 or 1, 2, 3).
Decomposition shines when you can spot a complement to a round number quickly.
With practice on Velox, you'll instinctively pick the best technique for each problem.