1, more than ten times more than ten, formula head joint, tail-to-tail, tail-to-tail, same head, tail-filling, the sum of tails is equal to 10, formula, add 1 after a head, head joint, tail-to-tail. The first multiplier is complementary and the other multiplier has the same number. After a head is added with 1, the head is multiplied by the head and the tail is multiplied by the tail.

2, dozens of eleven times dozens of eleven, the formula is multiplied by the head, the head is added, the tail is multiplied by any number, the formula falls at the beginning and end, the middle and the drop-down, the second multiplier of the formula does not drop, the unit of the first factor is multiplied by each number behind the second factor, plus the next number, and then falls.

3. The integer method in addition and subtraction, looking for the mixed operation calculation method of complement method. In the formula without brackets, only addition and subtraction or multiplication and division can be performed, from left to right. For the formula without brackets, multiply, divide, add and subtract first, and then add and subtract. If there are brackets in the formula, count the brackets first.