请帮我生成讲解视频，对象是一年下学期学生。---**Header:**
一(1) 班 练习 (Class 1 Practice)
**Center Title:**
100 以内数加与减 (一) (Addition and Subtraction within 100 (Part 1))
**Addition Section:**
* **Title:** 加法 (Addition)
* **Equation:** 17+11=28
* **Calculation Steps (分步算式):**
7+1=8
10+10=20
20+8=28
* **Vertical Calculation (竖式):**
+17
11
---
28
* **Diagram Labels:** 小棒 (small sticks/bundles), 竖式 (vertical calculation), 计数器 (abacus)
* **Diagram Description (小棒):** Shows a group of 1 bundle of 10 sticks and 7 individual sticks, plus a group of 1 bundle of 10 sticks and 1 individual stick. An arrow indicates combining them.
* **Diagram Description (计数器):** Shows an abacus representing 17 (1 bead in the tens place, 7 beads in the ones place). An arrow indicates adding 11 (1 bead in the tens place, 1 bead in the ones place), resulting in the abacus showing 28 (2 beads in the tens place, 8 beads in the ones place). Labels "十位" (tens place) and "个位" (ones place) are present below the abacus rods.
**Subtraction Section:**
* **Title:** 减法 (Subtraction)
* **Equation:** 28-11=17
* **Calculation Steps (分步算式):**
8-1=7
20-10=10
10+7=17
* **Vertical Calculation (竖式):**
28
-11
---
17
* **Diagram Labels:** 小棒 (small sticks/bundles), 竖式 (vertical calculation), 计数器 (abacus)
* **Diagram Description (小棒):** Shows a group of 2 bundles of 10 sticks and 8 individual sticks. An arrow indicates removing 1 bundle of 10 sticks and 1 individual stick.
* **Diagram Description (计数器):** Shows an abacus representing 28 (2 beads in the tens place, 8 beads in the ones place). An arrow indicates subtracting 11 (1 bead in the tens place, 1 bead in the ones place), resulting in the abacus showing 17 (1 bead in the tens place, 7 beads in the ones place). Labels "十位" (tens place) and "个位" (ones place) are present below the abacus rods.
**Word Problems Section:**
* **Title:** 解决问题 画图并列式解决 (Solve Problems Draw diagrams and list equations to solve)
* **Problem 1:**
* **Question Stem:** 1. 小丁 12 岁, 小林比小丁大 3 岁, 小林几岁? (1. Xiaoding is 12 years old, Xiaolin is 3 years older than Xiaoding, how old is Xiaolin?)
* **Calculation/Answer:** 12岁 12+3=15 (岁) (12 years old 12+3=15 (years old))
* **Diagram Description:** Bar diagram. A bar labeled "小丁:" represents Xiaoding's age and is labeled "12岁". A longer bar labeled "小林:" represents Xiaolin's age. The difference in length between Xiaolin's bar and Xiaoding's bar is indicated as "比小丁大3岁" (3 years older than Xiaoding). A bracket below the entire length of Xiaolin's bar asks "?岁" (how old?).
* **Problem 2:**
* **Question Stem:** 2. 苹果有 35 个, 梨比苹果少 12 个, 梨有几个? (2. Apples have 35, pears are 12 fewer than apples, how many pears are there?)
* **Calculation/Answer:** 35个 35-12=23(个) (35 items 35-12=23(items))
* **Diagram Description:** Bar diagram. A bar labeled "苹果:" represents the number of apples and is labeled "35个". A shorter bar labeled "梨:" represents the number of pears. The difference in length between the apple bar and the pear bar is indicated as "比苹果少12个" (12 fewer than apples), with a bracket and label "12个". A bracket below the pear bar asks "?个" (how many items?).