Math Journal 1/18/13

Percent can be expressed as an amount of change. Percent has its complication and eases like in compound interest or decimals. Percents can be changed to decimals by moving the decimal point two places to the left. For example, if you have 2%, once the decimal point is moved 2 points to the left, you would end up with 0.02 as the decimal. Percent of change is compatible with percent increase and decrease; the change is the amount of which number increases or decreases. Percent increase occurs when the amount goes up and Percent decrease occurs when the amount goes down. To find percent increase/decrease, set it up in fraction form; use the specified operation (addition/subtraction) as the numerator and the original number as the denominator. Solve, Simplify then change it to a decimal to get the increase or decrease. 

Ex. 15-10/15 = 5/15 = 33% decrease.

In the real-world, percent is used in many things like stock, marketing and surveys. It's important to have an understanding of the "story" behind the situation in order to apply specific strategies so it would be understood how to solve it. Word problems for percentage have various forms so we would need to know what's required to be known. Different types of problems may apply to different types of formulas or equations so it's always good to know what's specifically needed of solving.

Math Journal 1/9/13

Over the weeks, I've been studying linear equations. I've been studying the standard form, slope-intercept form, and the point-slope form. In order to know these forms, it would be mandated to know what is slope and how it works; Slope is the steepness of a line. Point-slope form goes by the formula of y-y1=m(x-x1). M represents the slope and (x1, y1) represents the given coordinates in a problem. It can be graphed by simplifying the equation after the information is given and using the info to graph. If one wishes to work further, the equation would end up in slope-intercept form. Slope-intercept form's formula is y=mx+b with m being the slope respectively and b being the y-intercept. The line to be graphed would start on the y-axis at the number that is to be used for b. Then, the slope should be used to form the line; ex. if the slope is 3 and the y-intercept is 4, my line would start on point (0,4) on the y-axis; when using whole numbers for slope, it's advised to change it to a fraction in form y/x. I would get 3/1 then I would need to move 3 units up and 1 unit right to be in the position of the next point and so forth on. Standard form's equation is ax+by=c so to set this up right, the data from the slope intercept equation would have to be positioned accurately with the standard form equation. The equation is required to be simplified then put in the order like the formula says; once done, a standard form equation is created. I would find point-slope form the most useful since it may be easier to place on a graph and the easiest to work out; slope-intercept form may require to find the y-intercept which takes time. The information provided for each equation form change my strategy for graphing since it makes how the concept works clearer. After learning about slope-intercept, point-slope and others, I recieved many new alternatives to graphing linear equations and lines that go with it. This lesson is one to sync into my brain and it's to be remembered once mentioned.