1, addition rounding
Example: 32+ 15+8, the original formula = 32+8+15 = 40+15 = 55. Add a few numbers. If several numbers add up to an integer of ten, you can change the position of the addend and add up several numbers.
2. Subtractive rounding
Example: 50- 13-7, the original formula = 50-( 13+7) = 50-20 = 30, and several numbers are continuously subtracted from a number. If the sum of subtraction can form an integer, you can add the subtraction first and then subtract it.
3. Multiplication and rounding
Example: 25× 14×4, the original formula = 25× 4×14 =100×14 =1400, followed by 25× 4 =1400. When you encounter a multiplier as large as 25, 125, see if you can make it 4 and 8.
Data expansion:
Oral calculation: mental calculation and oral calculation are carried out at the same time. Oral arithmetic is to calculate with the brain and remember the results at that time with oral narration. This method is used for quick calculation, and regular practice is helpful to improve intelligence. It has also become the mainstream calculation method today. Also called "mental arithmetic".
One of mathematics teaching methods. A calculation method based on thinking and language activities without any tools. It can train students to calculate quickly and develop their attention, memory and thinking ability. Proficiency in verbal calculation is helpful for written calculation and is convenient for daily use.
Mobile application of oral arithmetic in primary schools
"Primary school students' oral arithmetic" is an educational application based on tablet computer, which is developed for primary school students from grade one to grade six. It makes full use of the advantages of tablet computer to provide a comfortable, interesting, convenient and practical oral arithmetic training platform for primary school students, so that children can easily complete oral arithmetic homework and conduct oral arithmetic training anytime and anywhere, improve their oral arithmetic ability, and free parents from the work of exporting and checking oral arithmetic questions for their children every day.
Why use
Oral arithmetic is an important part of primary school mathematics learning, and it is also an important content of primary school students' mathematics homework and mathematics examination. The editorial board of Curriculum Standards for Full-time Compulsory Education pointed out: "Cultivating students' awareness of oral calculation, estimation and quick calculation plays an important role in developing students' computing ability and cultivating a good sense of numbers." In order to help primary school students finish their oral arithmetic homework quickly and improve their oral arithmetic ability, and also to help parents better coach their children.
Applicable people
At present, the 1-6 grade oral arithmetic problem cards in the People's Education Edition of the software provider and the Hebei Education Edition are all based on iPad tablets, which are suitable for parents who have the conditions to buy to help primary school students with oral arithmetic training.