Compound and interest Math suggestions

Compound and circle

Secondary school education teaching for math ( compound interest and circle)

We will be learning compound interest so  let's go all dear my friend move on details

1/  population of the town 80 lakho . So this town growth of population rates 30 and after 3 years rate of population. How may do this people?
Example: population of a town , P= 8000000  Tim ,t= 3 year.
Circle of years, n= 2; growth of population rate, r= 30/1000×100%=33%
There applied growth of population rate formulation
Population C= (1+3/100×1)1×3
                             = 8000000×(1.03)3 tk
                      Answer  = 8741816 tk.
Example:
2/ 4% rate of interest how much do this compound and circle interest , will be difference 2 year's of 1 tk?.
P = 100 and  4%  rates year's Compoun interested  = (💯×2×4/💯) 8 tk.
Circle interest = {💯(1+4/100)2 -100} tk.
                   = {💯×(1.04)2 -100} tk.
                   =(১০৮.১৬-১০০) টাকা = ৮.১৬
Difference of interest (8.16-8) or 0.16 tk.
P 💯 tk.
1 "    "      "   100×100/16
                  = 625 tk.
Example:
3/ rate of annual interest 10 tk. Interest of 500 tk rate of 3 years. How will be interest and circle difference?
 There, P= 500 tk.
                            Time, t= 3 years.
  Circle of years,n= 1
Annual interest rate r, =10
Compound interest , = p+i
                                       = p+ p×r×t/100
                         

        =(5000+ 5000×10×3/100
                                    =65000 tk
Circle interest
         C= p(1+ r/n)n×t
           = 5000(1+ 10/100×1)1×3
           = 5000×(1.1)3
           = 6655 tk.
Difference of compound interest
           = (6655-6500)
           = 155 tk.

                      Thanks