For example, 15* 12 can be calculated as follows:15 *12 =15 * (10+2), or = (10+)

Generally, the problem of multiplying by 5 or dividing by 5 is easier to calculate. The problem multiplied by 5 is multiplied by 10/2, divided by 5 and multiplied by 2/ 10.

When you encounter a large divisor, make an agreement first and then do the problem, which will make the number simple, or become two addition formulas, such as: 98/15 =15 * 6/15+8/15.

The above practices are also mentioned in the textbook, but some of them are not touched or can't be remembered when doing the questions. After teaching children, their homework speed will be improved, and then they will be interested in learning mathematics. When I taught my son this way, his joy was unforgettable. What method is more suitable for your child? Let's explore slowly.