Write 640, 3 and vertical division number according to the format, starting with the most significant bit.
In the hundreds: 6÷3=2, and the number in the hundreds is 2.
On the tenth place: 4 ÷ 3 = 1. 1, the number on the tenth place is 1, and the remainder 1 is combined with the next 0 to form 10.
Unit: 10 ÷ 3 = 3. 1, the number in the unit is 3, and the remainder is 1, which is not divisible.
Namely: 640 ÷ 3 = 2 13 1.
There are two points to note when calculating the extended data vertically:
1, the numbers need to be aligned. If three digits are divided by one digit, it needs to be divided from most significant bit, and the digit is recorded in most significant bit. If you add one digit to three digits, you need to align the three digits with one digit according to the digits, starting with the lowest digit.
2. Pay attention to the existence of remainder and decimal places: for example, 640 ÷ 3 = 2 13. 1. The top ten digits of 4 ÷ 3 = 1. 1 cannot be ignored in the calculation. 10 ÷ 3 = 3. 1, all of which have the remainder of 1.