1. (Hundred) analysis: "1+" is more than "1", and "1-" is less than "1".
2. Typical problem: Find how much one number is another (one percent) and how much more (less) one number is than another (one percent).
Knowing "1", find the fraction of a number (multiplication)
Find the fraction of the known unit "1" and find the unit "1" (division).
Problem solving formula
1, number of copies × number of copies = total
Total copies/number of copies = number of copies
Total copies/number of copies = number of copies
3. Speed × time = distance
Distance/speed = time
Distance/time = speed
4. Unit price × quantity = total price
Total price/unit price = quantity
Total price ÷ quantity = unit price
5. Work efficiency × working time = total workload.
Total amount of work ÷ work efficiency = working hours
Total workload ÷ working time = working efficiency
6. Appendix+Appendix = Total
Then subtract one addend = another addend.
7. Negative-negative = difference
Negative difference = negative
Difference+negative = negative
8. Factor × factor = product
Product ÷ One factor = another factor
9. Dividend bonus = quotient
Dividend = divisor
Quotient × Divider = Divider
10. Interest = principal × interest rate× time.
After-tax interest = principal × interest rate × time ×( 1- interest tax)
I gave you the formula to solve the problem. You can solve it yourself. Don't be lazy.