Method 2: break the ten methods. For example, 13-7 can be thought as follows: 10-7+3=6.
Method 3: continuous subtraction (commonly used method), such as 13-7. You can think of it this way: 13-3-4=6, which means dividing 7 by 3 and 4.
Method 4: Supplementary method. For example, 13-7 can also think like this: 13- 10+3=6.
There are many kinds of oral calculation methods, and how to find the best oral calculation method is the key to improve the speed and accuracy of oral calculation. When practicing, you can review a variety of oral calculation methods with students, so that students can get the best method through comparison.
Expanding data is easy before it is difficult.
Start with addition and subtraction within ten. It can be combined with objects that can be expressed by quantitative concepts in life. Such as apples, oranges, lychees, tomatoes, mangoes, etc. , can improve children's interest and let him know the important role of learning mathematics in life.
Consolidate the achievements
As long as you have free time, you can ask questions and speak quickly, which will give your child a sense of urgency and exercise his habit of thinking quickly and improving efficiency. Parents can say 3+2, 5+4, 9-3, etc. As long as the child answers correctly, he should be praised, "Great", "Great" and "My child (student) is really smart".
The addition and subtraction within 10 should make him particularly skilled before entering 20 and before transitioning to 100. Not too fast, step by step, the best effect.
Consulting skills
Addition and subtraction within ten, once again, must make children extremely skilled. Achieve the effect of blurting out. Don't worry. It is necessary to tell children that addition and subtraction are complementary, especially within ten minutes, which helps children understand.