如何使用科学记数法简化数字？
一个数字的指数或幂表示前者乘以自身的次数。例如，如果让 a 是任何一个与自身相乘 n 次的实数，那么 a 的指数或幂将为 n。 a 的指数是 n，公式 a n读作 a 的 n 次幂。在研究数轴时，使用指数和幂来方便地表示非常大或非常小的数字。
科学计数法
科学记数法是表示极大或极小数字的更简单方法。如前所述，数字可以永远扩展，但如此庞大的数字不能写在一张纸上。此外，小数点后数百万位的数字必须以更易于理解的方式表示。因此，很难以放大的形式表示几个整数。因此，使用了科学记数法。
在科学记数法下，任何数字都写成它的值介于数字 1 和 10 之间，不包括 10，但包括 1。
n × 10m
Where n is a real number such that 1 ≤ n < 10 and is known as the significant.
科学记数法规则
- 起点应始终为十。
- 确保给定的指数是实数。不管是正面的还是负面的，都没有区别。
- 系数的绝对值大于等于一，但应该小于十。
- 系数可以是正值或负值，也可以是整数或十进制整数。
- 数字的有效数字的其余部分由尾数携带。
类似问题
问题 1：用科学计数法写出 897,000,000,000。
解决方案：
Clearly the given number has only 3 considerable numbers/ figures since the zeroes are to be regarded as mere placeholders.
Following the first rule of scientific notation, put a decimal after the first digit in the given number.
897,000,000,000 = 8.97 × 100 × 1000000000
= 8.97 × 102 × 109
= 8.97 × 1011
问题 2：用科学计数法写出 990000000000。
解决方案：
Clearly the given number has only 3 considerable numbers/ figures since the zeroes are to be regarded as mere placeholders.
Following the first rule of scientific notation, put a decimal after the first digit in the given number.
990000000000 = 9.9 × 10 × 10000000000
= 9.9 × 101 × 1010
= 9.9 × 1011
问题 3：用科学计数法写出 0.00000077。
解决方案：
Move the decimal point up to 7 positions to the right of 0.00000077.
To make the number 7.7, the decimal point was moved 7 places to the right.
The decimal is moved to the right since the numbers are fewer than ten. As a result, we employ a negative exponent in this case.
⇒ 0.00000077 = 7.7 × 10-7
问题 4：用科学计数法写出 0.0000426。
解决方案：
Move the decimal point up to 5 positions to the right of 0.0000426.
To make the number 4.26, the decimal point was moved 5 places to the right.
The decimal is moved to the right since the numbers are fewer than ten. As a result, we employ a negative exponent in this case.
⇒ 0.0000426 = 7.7 × 10-5
问题 5：用科学计数法写出 699000000。
解决方案：
Clearly the given number has only 3 considerable numbers/ figures since the zeroes are to be regarded as mere placeholders.
Following the first rule of scientific notation, put a decimal after the first digit in the given number.
699000000 = 6.99 × 100 × 1000000
= 6.99 × 102 × 106
⇒ 699000000 = 6.99 × 108
问题 6：用科学计数法写出 358000000。
解决方案：
Clearly the given number has only 3 considerable numbers/ figures since the zeroes are to be regarded as mere placeholders.
Following the first rule of scientific notation, put a decimal after the first digit in the given number.
358000000 = 6.99 × 100 × 1000000
= 3.58 × 102 × 106
⇒ 358000000 = 3.58 × 108
问题 7：将 0.00000055 转换为科学计数法。
解决方案：
Move the decimal point up to 7 positions to the right of 0.00000055.
To make the number 5.5, the decimal point was moved 7 places to the right.
The decimal is moved to the right since the numbers are fewer than ten. As a result, we employ a negative exponent in this case.
⇒ 0.00000055 = 5.5 × 10-7
问题 8：用科学计数法写出 5890000。
解决方案：
Clearly, the given number has only 3 considerable numbers/ figures since the zeroes are to be regarded as mere placeholders.
Following the first rule of scientific notation, put a decimal after the first digit in the given number.
5890000 = 5.89 × 100 × 10000
= 5.89 × 106