1, when the unit is not enough, subtract the subtraction with 10, and add the remainder with the number in the unit, that is, break the ten method.
Two, ten MINUS nine, a few plus one. Ten MINUS seven, a few plus three. Ten MINUS five, a few plus five. A dozen MINUS three, a few plus seven.
3. A dozen MINUS eight, a few plus two. Ten MINUS six, a few plus four. Ten MINUS four, a few plus six. A dozen MINUS two, a few plus eight.
Examples of application of ten-break method:
For example, 12-9 =, 1 minus 9, 1+2 gets 3, so12-9 = 3;
Extended data:
Ten-break method is to solve the problem that the number of units is not enough by reducing more than ten units, such as 13-9, as shown in the following figure:
We take out 9 from 10, leaving 1, and then add this 1 to 3 to get 4.
Mathematical method plays an important role in scientific and technological research: first, it provides concise and accurate formal language; The second is to provide quantitative analysis and calculation methods; Third, it provides a tool for logical reasoning.
The development of modern science and technology, especially electronic computers, and the strengthening of the position and function of mathematical methods are exactly complementary.