Multiplied by 3, only the mantissa of 7 is 1, so it is equal to 7.

3*7=2 1, and then dozens of digits are 7,7-2 = 5.

So Le =5, the hundredth is 5.

3*5= 15,5- 1=4

So all =8, and then thousands are 8.

3*8=24,8-2=6

So learn =2, and then ten thousand digits are two.

3*2=6,2-0=2

So the number =4

The math club is 42857.

Calculation rules of multiplication:

Number alignment, starting from the right, multiply the first factor by the number on each bit of the second factor, and the end of the number will be aligned with which bit of the second factor.

When the multiplicand meets the joint operation of large numbers such as 989697, the period method is as follows: the last digit of the multiplicand is supplemented by 10, the first digit is fixed by 9, and the first digit is supplemented by 9 times when it meets 6, 7 and 8 (all from the lower digit), and finally the first digit of the multiplicand is subtracted once.

For example: 9798×8679 = 85036842(8679' s complement 132 1) Order: add 2642 to the low order of multiplier 8 to get 979-82642. Multiplier ten digits nine don't move. Add 2642 to the low order of the hundredth 7 of the multiplicand to get 9-8246842. Subtract 132 1 from the first bit of the multiplier to get 85036842 (product).