Fourth grade book 2: planting trees
The first volume of grade five: coding, understanding the meaning of ID card, postal code, etc. , can be simple coding.
The fifth grade book: problem optimization, mainly looking for items, is to find out the one with different weights from a corresponding number of items.
The first volume of the sixth grade: chickens and rabbits in the same cage
Book for the sixth grade: pigeon coop principle.
Quantitative relationship: sixth grade: working hours * working efficiency = total workload.
Total amount of work ÷ work efficiency = working hours
Total workload ÷ working time = working efficiency
Speed × time = distance
Distance/speed = time
Distance/time = speed
Principal * interest rate = interest
Unit price * quantity = total price
Work efficiency * time = total workload.
Single output * quantity = total output
Number of copies * Number of copies = Total number Speed = Time * Distance
Principal * interest rate * time = interest
The main quantitative relationship in tree planting is: the number of intervals × the number of meters in each interval = a * * * * number of meters;
The main quantitative relationship of sawing wood is: times of sawing × time of sawing = time of sawing;
The quantitative relationship in the stair climbing problem is: the number of stairs ÷ the number of stairs between every two floors = the number of stairs.
The main relationship of the bell ringing problem is: the number of waiting times × the time of waiting once = the time of waiting once.
Survival rate = number of surviving trees/total number of trees
Qualified rate = qualified/total
Grade five: engineering problems:
Workload = work efficiency × required time;
Time required = workload ÷ work efficiency;
Work efficiency = workload ÷ required time
Travel problems:
Distance = speed × time;
Distance ÷ time = speed;
Distance/speed = time
Tap water problem:
Downstream stroke = (ship speed+water speed) × downstream time
Upstream stroke = (ship speed-water speed) × upstream time
Downstream speed = ship speed+current speed = ship speed-current speed.
Still water velocity = (downstream velocity+upstream velocity) ÷2
Recurrent engineering problems seem to be the focus.