1, rewrite the number of low-level units into the number of high-level units.

For example: 700 meters =(0.7) kilometers.

Interpretation: meters are replaced by kilometers, and odd numbers are replaced by odd numbers. The meter is a low-level unit and the kilometer is a high-level unit. Because 1 km = 1000 m, if the meter is changed to km, it will be divided by the rate of 1000.

700÷ 1000=0.7, and the decimal point is moved three places to the left.

We will find that low-level units are replaced by high-level units, and units become bigger and smaller.

Summary: rewrite the single number of low-level units into the number of high-level units, divide by the advancing rate between units, and then move the decimal point to the left according to the advancing rate.

2. The number of high-level units is rewritten as the number of low-level units.

For example:1.675g = (1675) g.

Release: kilograms are changed into grams, and low-level units are changed into high-level units, because 1kg = 1000g. Kilograms are replaced by grams, so the decimal point is multiplied by 1000, and 1.675 is shifted three places to the right to become 1675.

We will find that high-level units are replaced by low-level units: units become decimal and become larger.

Summary: When the number of high-level units is rewritten as the number of low-level units, it needs to be multiplied by the inter-unit advancing rate, and then the decimal point is moved to the right according to the inter-unit advancing rate.

Introduction to decimal point:

Decimal point, a mathematical symbol written as ".",is used to separate the integer part from the decimal part in decimal system. Although the decimal point is small, it plays a great role.