什么是平方根？
What is a square root?
一个数 x 的平方根是一个数 y，使得 y 的平方等于 x，即 y² = x。例如 9 的平方根是 3 和 −3，因为 3² = 9。
The square root of a number x is a number y such that y squared equals x, that is, y² = x. For example, the square roots of 9 are 3 and −3, because 3² = 9.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Beckmann, S., 《中小学数学教师数学》(第4版), Pearson
Beckmann, S., 'Mathematics for Elementary Teachers' (4th ed.), Pearson
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL18708410W：Mathematics for elemen
#平方根 #平方 #运算
什么是最小公倍数？
What is the least common multiple?
几个整数的公倍数中最小的正整数称为它们的最小公倍数（LCM）。例如 4 和 6 的最小公倍数是 12，因为 12 是同时能被 4 和 6 整除的最小正整数。
The least common multiple (LCM) of several integers is the smallest positive integer that is divisible by all of them. For example, the LCM of 4 and 6 is 12, since 12 is the smallest positive number divisible by both 4 and 6.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Beckmann, S., 《中小学数学教师数学》(第4版), Pearson
Beckmann, S., 'Mathematics for Elementary Teachers' (4th ed.), Pearson
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL18708410W：Mathematics for elemen
#最小公倍数 #倍数 #整除
什么是因数和倍数？
What are factors and multiples?
如果整数 a 能被整数 b 整除（没有余数），那么 b 是 a 的因数，a 是 b 的倍数。例如 3 是 12 的因数，12 是 3 的倍数。
If integer a is divisible by integer b with no remainder, then b is a factor (or divisor) of a, and a is a multiple of b. For example, 3 is a factor of 12, and 12 is a multiple of 3.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Beckmann, S., 《中小学数学教师数学》(第4版), Pearson
Beckmann, S., 'Mathematics for Elementary Teachers' (4th ed.), Pearson
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL18708410W：Mathematics for elemen
#因数 #倍数 #整除
什么是百分数？
What is a percentage?
百分数（%）表示一个数占另一个数的百分之几，也就是分母为 100 的分数。例如 50% 等于 50/100，即一半。
A percentage (%) expresses a number as a fraction of 100, that is, a fraction whose denominator is 100. For example, 50% equals 50/100, which is one half.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Beckmann, S., 《中小学数学教师数学》(第4版), Pearson
Beckmann, S., 'Mathematics for Elementary Teachers' (4th ed.), Pearson
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL18708410W：Mathematics for elemen
#百分数 #比例 #算术
什么是乘法？
What is multiplication?
乘法是把相同数加起来的简便运算，例如 3 × 4 表示 4 个 3 相加，结果是 12。它满足交换律，即 3 × 4 = 4 × 3。
Multiplication is a shortcut for repeated addition of the same number, for example 3 × 4 means adding 3 four times, giving 12. It satisfies the commutative law, so 3 × 4 = 4 × 3.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Beckmann, S., 《中小学数学教师数学》(第4版), Pearson
Beckmann, S., 'Mathematics for Elementary Teachers' (4th ed.), Pearson
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL18708410W：Mathematics for elemen
#乘法 #加法 #算术
什么是十进制？
What is the decimal (base-ten) system?
十进制是我们最常用的记数法，每一位上的数字代表该位的“权”是 10 的幂。例如 345 表示 3 个百、4 个十和 5 个一。
The decimal (base-ten) system is the number notation we use most, where each digit's place represents a power of 10. For example, 345 means 3 hundreds, 4 tens, and 5 ones.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Beckmann, S., 《中小学数学教师数学》(第4版), Pearson
Beckmann, S., 'Mathematics for Elementary Teachers' (4th ed.), Pearson
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL18708410W：Mathematics for elemen
#十进制 #位值 #记数法
什么是偶数？
What is an even number?
偶数是能被 2 整除的整数，例如 2、4、6、0。判断一个数是否为偶数，只需看它的个位数字是 0、2、4、6 还是 8。
An even number is an integer divisible by 2, such as 2, 4, 6, and 0. You can tell a number is even by checking whether its last digit is 0, 2, 4, 6, or 8.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Beckmann, S., 《中小学数学教师数学》(第4版), Pearson
Beckmann, S., 'Mathematics for Elementary Teachers' (4th ed.), Pearson
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL18708410W：Mathematics for elemen
#偶数 #整除 #算术
什么是加法交换律？
What is the commutative law of addition?
加法交换律指两个数相加时，交换位置后和不变，即 a + b = b + a。例如 3 + 5 与 5 + 3 都等于 8。
The commutative law of addition states that changing the order of two numbers being added does not change their sum, that is, a + b = b + a. For example, both 3 + 5 and 5 + 3 equal 8.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Beckmann, S., 《中小学数学教师数学》(第4版), Pearson
Beckmann, S., 'Mathematics for Elementary Teachers' (4th ed.), Pearson
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL18708410W：Mathematics for elemen
#加法 #交换律 #算术定律
什么是负数？
What is a negative number?
负数是小于零的数，通常前面带一个负号“−”，例如 −3。负数常用来表示欠款、零下温度或方向相反的量。
A negative number is a number less than zero, usually written with a minus sign, such as −3. Negative numbers are often used to represent debt, temperatures below freezing, or quantities in the opposite direction.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Beckmann, S., 《中小学数学教师数学》(第4版), Pearson
Beckmann, S., 'Mathematics for Elementary Teachers' (4th ed.), Pearson
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL18708410W：Mathematics for elemen
#负数 #数轴 #算术