Exercise · L3
L3 mixed, sequence columns · 3-4 digits
Best for
Best for focused single-question practice and careful method review.
Practice rule: try this before opening the hint or answer.
520 - 184 + 129
Solve the sequence before checking the final answer. Focus on clean transitions between subtraction and addition.
Attempt first
1. Solve first 2. Write your response 3. Verify or reveal
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