Methods and steps:
1, there are various understanding schemes, ability goals, learning goals, various retreat methods within 100, and various abdications.
2. the subtraction of abdication is actually very simple, and the number of digits can be aligned to do subtraction. You should know that the column vertical calculation of carry can also be answered by decimal addition.
3. Be careful not to forget to count horizontally when counting vertically, ten against ten. One more thing to say is right.
4. Another way is to answer the calculated results completely, and don't forget to write the unit.
：
1, write the result directly.
35+6=()30+56=()78-7=()23+25=()54+ 18=()90-39=()48+20-7=()29-20+7=)()6+30+34=()
2. Vertical calculation.
45+28+27=()80-28-34=()96-47+29=()68+28-57=()93-27-35=()
3. Application questions.
(1) There are fewer story books than comic books on the shelf 15. There are 8 magazines and 32 story books on the shelf. How many comic books are there? How many story books and comic books are there?
(2) Xiao Ming's mother bought a rope with a length of 16 meters, cut off some for skipping, and there were 6 meters left. How many meters does it take to jump rope?
(3) There are 35 boys and 37 girls in Grade Two. How many are there in the first grade? Among them, 50 people took part in the "Red Tour" this summer. How many people didn't take part in the "Red Tour"?
(4) There are 65 cars in the parking lot, and 3 1 car has been driven away. How many cars are left? Here come six more. How many cars are there in the parking lot now?
(5) Obana's parents do calculations in a competition. Xiaohua did six arithmetic problems correctly in one minute. Her father did four times as many as Xiaohua, while her mother did five less. How many things can mom do right in a minute?