请按照数学题目生成视频讲解过程---**Extraction Content:** **Question Stem:** 一个等差数列: 1, 4, 7, 10, 13, ……那么100是第___项。 **Sequence:** 1, 4, 7, 10, 13, ... (This is an arithmetic sequence) **Handwritten Calculation/Answer:** Calculation: (100 - 1) ÷ 3 + 1 = 34 Answer in blank: 34 **Other Relevant Text:** The question asks for the term number in the sequence that equals 100. **Diagram/Figure Description:** - Type: Simple sketch/doodle. - Main Elements: - An outline resembling a curved shape or partial circle at the top left. - Four small oval shapes arranged in a roughly rectangular pattern within the curved outline. - A small triangle shape positioned between the two lower oval shapes. - Another curved line shape below the main sketch. - These shapes do not appear to be part of the mathematical problem.