Example: oral calculation:
480÷6= 200÷5= 420÷6= 360÷4= 280÷4=
Estimate:
7 18÷9≈ 422÷7≈ 354÷6≈ 484÷7≈ 4 12÷5≈
Vertical calculation and checking calculation:
184÷8= 428÷4= 453÷9= 308÷3= 420÷3=
Off-line calculation:
5 17÷7×5 125×(308-299) 325- 125÷5 600- 198+359
Knowledge point 2: solve problems with division and mixed operation;
Example: Solve the problem:
Grade 03 boys 104, girls 88.
(1) If each person issues 4 exercise books, how many copies do you need for a * * *?
(2) Use a desk for every 2 people. How many tables does a * * * need?
2. Miss Wang wants to put the book of 156 on two bookshelves, each with three floors. How many books are put on each floor on average?
Tianjin is 360 kilometers away from Jinan. The train leaves Jinan at 6 am and 90 km from Tianjin at 9 am. How many kilometers does the train travel per hour on average? (drawing)
4. 30 tons of coal, 9 tons of large trucks and 3 tons of small trucks.
(1) If you use five minivans, how many times can you transport all the coal?
(2) First, transport it by small trucks 1 time, and the rest by large trucks. How many times does it take for all the transportation?
Teams 5 and 4, each with 28 people. Limited collar per person: 2 bottles of mineral water and 3 pieces of chocolate.
(1) Prepare 300 pieces of chocolate. Is that enough?
(2) How many bottles of mineral water can I take at most? 2 bottles per box, 8 boxes per box. How many boxes do you need to buy?
6, 4 28 yuan, a box 12, 3 boxes can sell how much?
7. Each pencil costs 40 cents. A box 15 pencils. How much can I buy a box of 18 * *?
Knowledge point 3: symmetry
Can accurately judge the axial symmetry phenomenon; Can draw symmetry axis; Draw the other half according to half of the picture.
Knowledge point 4: Double digits by double digits
Example: oral calculation:
Estimation: 51× 68 ≈ 33× 22 ≈ 319 ≈ 62× 21≈ 58×13 ≈/7× 62 ≈ 26× 34 ≈ 32 ×.
Written calculation: 89× 27 824 ÷ 4 98× 23 73× 65 60× 57 26× 32 32× 45 76× 48.
Off-line calculation:
37×(294- 198) 2 16- 100÷4