SUMMARY OF MATH REVISION GRADE 10
SIGNIFICANT FIGURE
Just remember the difference:
For adding, use "least accurate place".
For multiplying, use "least number of significant digits".
PREFIX
Micro- = 10^-6
Nano- = 10^-9
Femto- = 10^-12
Mega- = 10^6
Giga- = 10^9
Tera = 10^12
TIME PROBLEM
24hrs system : 00.01 – 24.00 or 00.00 – 23.59
12hrs system : 00.01 – 12.00 am and
00.01 – 12.00 pm = 12.01 - 24.00 (in 24hrs system).
GCF & LCM
GCF = Greatest Common Factor = take the smaller common factors.
LCM = Least Common Multiple = take the bigger common factors and also uncommon factor.
Map problem
Scale= map distance : actual distance.
Proportionality
Direct y=k*x
Inverse y= k/x
k = constant of proportionality
Work word prob.
(1/a) + (1/b) = (1/T)
a= time needed for person a to finish the work alone.
b= time needed for person b to finish the work alone.
T= time needed for they to finish the work altogether.
Simple Interest
I = P*R*T
A= P (1 + R*T)
Where:
I= simple interest
P= principal or original investment/loan
R= rate of interest (% p.a. = % per annum = % per year)
T= time/period of loan/saving (years)
A= total amount of money after the simple interest added to the principal investment/loan.
Compound Interest
A= P * (1+(R/n))^(T*n)
Where:
A= total amount of money after the compound interest added to the principal investment/loan.
P= principal or original investment/loan
R= rate of interest (% p.a. = % per annum = % per year)
T= period of loan/saving (years)
n= number of compounding per annum
keywords:
compounded annually n = 1 once per year.
compounded semi-annually n = 2 twice per year.
compounded quarterly n = 4 four times per year.
compounded monthly n = 12 twelve times per year.
compounded bi-annually n = 1/2 once per 2 years.
