Top 5 Things I Learned in Math 9
For me, this is the most important unit that I learned because it applies to real life about money. In this unit, I learned different types of accounts such as Savings Account, Chequing Account, RRSP, RESP, TFSP, and more. I learned that a savings account has higher interest rate than a checking account and a checking account is more on everyday money transactions with a lower interest rate. I think this is the most important unit for me because, in this unit, it will teach you some ways to save money and it will help you in the future. I also learned how to calculate my interest rate with my savings – which is helpful because I got some knowledge about how much interest I will earn by the end of the year with my savings.
Example (word problem):
Jane has a $1,000 in a savings account earning 3%. How much interest will she earn at the end of the year?
Interest = principal ($) x rate x time (years)
She will earn $30 in her savings account with the total amount of $1,030 by the end of the year.
Polynomials have a term where there is a coefficient, variable, exponent, and a constant number by itself. I learned about like and unlike terms; sorting and combining like terms, and I also learned about distributing polynomials where you have to distribute the term outside the brackets and distribute it to the terms inside brackets. I also learned about the degree – which means the largest exponent of a variable. This lesson is necessary to know because this is also related to exponents law and distributive property because both of these appear in polynomials often – which can be challenging because sometimes we forget about the exponent laws, and the distribution of a negative sign outside the brackets. And there’s also a chance of confusion when solving polynomials because it can be a really long algebraic expression.
In this unit, I learned about the BFSD rule which stands for “Best Friends Share Desserts” or brackets, fractions, sort, and divide. This is similar to BEDMAS and this mostly appears in equations. I also learned about fractional equations where I must use the BFSD rule, especially there’s a fraction/(s). This is important to learn because it is related to the financial unit where you find the interest by calculating the interest rate, principal and time (I = p r t) and same as for linear equation where you find x. It will help me in the future by being strategic and wise in spending money on clothing store deals (for example).
Here’s an example of using algebra tiles to solve equations visually:
And here’s another way of solving equations algebraically:
Checking the solution:
To tell if the solution to the equation is right, you can plot it on a graph or evaluate it – which I think is the best option, here’s how:
So my equation was 2x – 4 = 6x + 5 and the solution was x = -9/4 then I’m going to evaluate it by inserting my solution to x and evaluate it. If the two sides have the same answer, then the solution is correct.
Symmetry and Surface Area
In this unit, I learned how to find the surface area of an object and volume. This is an important unit for me because it’s related to the course that I want to take in college, and this would be very helpful to use when I need to measure 3D objects or if I want to construct my house in the future. This is also related to art because it has something to do with symmetry in shapes/objects, and also for architecture and engineering courses.
Scale Factors and Similarity
I really learned a lot from this lesson because I learned how to determine if two triangles are similar or not, and how to find the missing side length/(s) of a triangle. I also learned about enlargements and reductions and also how to indirectly measure tall objects/buildings using similar triangles with shadows and mirrors – which I think is necessary to know because I might need it for making sure that my furniture (for example) will fit through the door or if I want to simply find some tall buildings/objects.
How to measure tall objects indirectly using similar triangles: