为什么时间要用数字来记？
Why do we record time with numbers?
用数字记时间能让全世界的钟表说同一种“语言”，约时间不会乱。数字把流动的时间切成了能比较的小格子。
Writing time as numbers lets clocks everywhere speak the same language, so meetings do not get mixed up. Numbers cut flowing time into comparable little boxes.
难度 入门 · 适合 小学高段(9-12)
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出处备注：本题原挂出处与答案内容不符，已撤回；具体书目待补，暂不展示来源。
本题原挂出处与答案内容不符，已撤回；具体书目待补。
Previous citation withdrawn as unsupported for this answer; a specific source is pending.
#时间 #数字
为什么闰年要多一天？
Why does a leap year add an extra day?
地球绕太阳一圈其实要365天多一点点。每四年把少算的大约一天补回来，加在二月，就是闰年。
Earth's trip around the Sun actually takes a bit more than 365 days. Every four years we add the missing day to February, making a leap year.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Courant & Robbins,《What Is Mathematics?》Oxford University Press,1996 第二版;中译《什么是数学》
R. Courant and H. Robbins, What Is Mathematics?, Oxford University Press, 1996; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL811195W：What is mathematics?（按标题
#闰年 #年
一天为什么有白天和黑夜？
Why is there day and night in one day?
地球自己转一圈，朝着太阳的一面是白天，背对太阳的一面是黑夜。转完一圈大约就是一天。
Earth spins once, and the side facing the Sun has day while the opposite side has night. One full spin is about one day.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 2 条独立证据
来源 · Source
《十万个为什么》第六版地球分册,少年儿童出版社,2013
Ten Thousand Whys: Earth volume, 6th ed., Juvenile and Children Publishing House, 2013
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-7-5324-9328-9 · 核验依据 2 ISBN 9787532493289
#白天 #黑夜
我们怎么测量很远的距离？
How do we measure very far distances?
对很远的路，我们用更大的单位，比如公里，等于1000米。卫星还能用光或信号来回的时间算出地球到月亮有多远。
For far roads we use bigger units like the kilometer, equal to 1000 meters. Satellites can even use the travel time of light or signals to measure the distance to the Moon.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：本题原挂出处与答案内容不符，已撤回；具体书目待补，暂不展示来源。
本题原挂出处与答案内容不符，已撤回；具体书目待补。
Previous citation withdrawn as unsupported for this answer; a specific source is pending.
#距离 #测量
为什么一年有12个月？
Why does a year have 12 months?
古时候人们看月亮圆缺大约12次，刚好接近地球绕太阳一圈的时间。于是就把一年分成12个月来记。
Long ago people saw the Moon grow full about 12 times, close to one trip of Earth around the Sun. So they split the year into 12 months.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Courant & Robbins,《What Is Mathematics?》Oxford University Press,1996 第二版;中译《什么是数学》
R. Courant and H. Robbins, What Is Mathematics?, Oxford University Press, 1996; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL811195W：What is mathematics?（按标题
#月 #年
为什么一年有四季？
Why does a year have four seasons?
地球绕着太阳转，同时身子有点歪。歪着转让不同时候照到的阳光不一样多，就出现了春、夏、秋、冬。
Earth orbits the Sun while tilted a bit. The tilt makes sunlight stronger or weaker through the year, creating spring, summer, autumn and winter.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：本题原挂出处与答案内容不符，已撤回；具体书目待补，暂不展示来源。
本题原挂出处与答案内容不符，已撤回；具体书目待补。
Previous citation withdrawn as unsupported for this answer; a specific source is pending.
#季节 #年
为什么我们要看钟表？
Why do we look at clocks?
钟表告诉我们现在是第几天里的什么时间，好安排吃饭、睡觉和玩耍。没有钟，大家就很难约好一起做事情。
A clock tells us what time of day it is, so we can plan eating, sleeping and playing. Without clocks, it would be hard to meet and do things together.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：本题原挂出处与答案内容不符，已撤回；具体书目待补，暂不展示来源。
本题原挂出处与答案内容不符，已撤回；具体书目待补。
Previous citation withdrawn as unsupported for this answer; a specific source is pending.
#钟表 #时间
为什么一小时分成60分钟？
Why is an hour split into 60 minutes?
古巴比伦人喜欢用60这个数，因为它能被很多数整除，分起来方便。这个习惯一直留到了今天的钟表上。
Ancient Babylonians liked the number 60 because it divides evenly by many numbers, making splits easy. The habit stayed on our clocks to this day.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Courant & Robbins,《What Is Mathematics?》Oxford University Press,1996 第二版;中译《什么是数学》
R. Courant and H. Robbins, What Is Mathematics?, Oxford University Press, 1996; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL811195W：What is mathematics?（按标题
#分钟 #小时
我们怎么知道东西有多长？
How do we find out how long something is?
我们拿一个固定的小单位，比如厘米或一把尺，沿着东西比一比。数出有多少个这样的单位，就知道它有多长。
We take a fixed small unit, like a centimeter or a ruler, and compare it along the thing. Counting how many units fit tells us its length.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：本题原挂出处与答案内容不符，已撤回；具体书目待补，暂不展示来源。
本题原挂出处与答案内容不符，已撤回；具体书目待补。
Previous citation withdrawn as unsupported for this answer; a specific source is pending.
#长度 #测量
为什么我们需要日历？
Why do we need a calendar?
日历把日子、月份和年份排成一张大表，帮我们记住节日和约会。没有日历，就很容易忘记重要的那一天。
A calendar lays out days, months and years in one big table, helping us remember holidays and meetings. Without it, we would easily forget important dates.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：本题原挂出处与答案内容不符，已撤回；具体书目待补，暂不展示来源。
本题原挂出处与答案内容不符，已撤回；具体书目待补。
Previous citation withdrawn as unsupported for this answer; a specific source is pending.
#日历 #日期
为什么一周有7天？
Why does a week have 7 days?
很多古老的文化都数到7就停，因为能看见的“会动的天体”有7个：太阳、月亮和五颗亮星星。于是定下一星期7天。
Many old cultures stopped at 7 because they saw seven moving lights in the sky: the Sun, the Moon and five bright planets. That is how the 7-day week began.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Courant & Robbins,《What Is Mathematics?》Oxford University Press,1996 第二版;中译《什么是数学》
R. Courant and H. Robbins, What Is Mathematics?, Oxford University Press, 1996; Chinese ed.
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL811195W：What is mathematics?（按标题
#周 #天