Division (II)
A 2-digit or 3-digit number divided by a 2-digit number in long division, including trying a quotient; checking a division with multiplication; estimating quotients; the divisibility tests for 2, 5, 10 and 3; odd and even numbers; and word problems.
Key words
| Chinese | English |
|---|---|
| 除數 | divisor |
| 被除數 | dividend |
| 商 | quotient |
| 餘數 | remainder |
| 整除 | divisible |
| 奇數 | odd number |
| 偶數 | even number |
The 6 short lessons and the chapter test
Lessons are in Chinese for now.
- 除以整十數和試商
- 兩位數除以兩位數
- 三位數除以兩位數
- 估算
- 整除
- 奇數和偶數
- 章節測驗 (chapter test)
Sample questions (in Chinese)
Question 1計算。
120 ÷ 40 =
Answer and explanation
答案：120 ÷ 40 = 3
為甚麼？想一想：40 乘多少最接近 120 又不大於它？40 × 3 = 120，剛好除盡。
Question 2用直式計算，寫出商和餘數。
87 ÷ 40 = …
Answer and explanation
答案：87 ÷ 40 = 2 … 7
為甚麼？由最高位開始除：最高兩位 87 才夠 40 除；87 ÷ 40 = 2 餘 7（40 × 2 = 80）。所以 87 ÷ 40 = 2 … 7。餘數 7 要小於除數 40。
Question 3用直式計算，寫出商和餘數。
543 ÷ 61 = …
Answer and explanation
答案：543 ÷ 61 = 8 … 55
為甚麼？由最高位開始除：最高三位 543 才夠 61 除；543 ÷ 61 = 8 餘 55（61 × 8 = 488）。所以 543 ÷ 61 = 8 … 55。
Question 4估算 87 ÷ 33 的商。下面哪一個最合理？
- 54
- 3
- 300
- 30
Answer and explanation
答案：B．3
為甚麼？87 大約是 90，33 大約是 30。90 ÷ 30 = 3，所以商大約是 3。
Based on learning unit 4N2 of the Education Bureau’s Primary Mathematics Curriculum (2017).