Somehow, Mr. E fell behind …
Pre-Algebra
Day 43 (Chapter 4-7, Friday, October 27) Least Common Multiple
The least of the common multiples of 2 or more numbers is called the least common multiple (LCM) of the numbers. To find the LCM, first find the GCF and then multiply the GCF by ALL those separate terms that are left over. See examples on page 201.
Day 42 (Chapter 4-6, Thursday, October 26) Simplifying Fractions
A ratio is a comparison of 2 number by division. A ration can be expressed as
– 2 to 3
– 2:3
– 2/3
A fraction is in simplest form when the GCF of the numerator and denominator is 1.
If you remember from elementary schoo, you can divide both the numerator and denominator by the same number to reduce a fraction to simplest form.
Day 41 (Chapter 4-5, Wednesday, October 25) Greatest Common Factor
The greatest of the factors of 2 or more numbers is called the greated common factor (GCF).
To find the GCF, find the prime factorization of the number and then find the product of their COMMON factors. See page 190 for examples.
Day 40 (Chapter 4-4, Tuesday, October 24) Prime Factorization
Using a factor tree, we can find the prime factors for any numbers. Remeber, a prime number is a whole number that has exactly 2 factors, 1 and itself. Composite numbers have more than 2 factors.
0 and 1 are neither prime or composite. See examples on page 185 and 186 for factor trees.
Algebra
Day 43 (Chapter 7-3, Friday, October 27)
Linear Equations and their Graphs
Linear equations have x and y variables that exponents of 1 AND they have no negative exponents for the variables and they have NO PRODUCTS of variables x and y.
The x-intercept we find by setting the y value to 0. We are finding where the linear equation crosses the x axis.
The y-intercept is found by setting the x value to 0 and solving for y.
With these 2 points, we can then plot a line.
A horizontal line has 0 slope and a vertical line has NO slope (or undefined slope).
Day 42 (Chapter 7-2, Thursday, October 26)
Money Matters Worksheet
We learned by using the activity of spending and saving money about linear equations and positive and negative slope. A line with zero slope is horizontal and a line with NO slope is a vertical line.
Lines that are parallel must by definition share (have the same) the same slope!
Day 41 (Chapter 7-1 and 2, Wednesday, October 25)
Graphing Ordered Pairs and Equations
We learned about the (x, y) coordinates and the x and y axes. The x axes is horizontal and the y axis is vertical. By solving equations for y, i.e., isolating the y on one side of the equation and placing the x and the constants on the other side, we can choose values for x (in a table) and find the corresponding y value to plot.
The graph is divided into 4 quadrants with I being in the upper right, II being in upper left, III being in lower left and IV being in lower right quadrant. Coordinates lying on the x or y axis are considered NOT in a quadrant.
In plotting a linear equation, we need to use AT LEAST 3 points …. unless we are using the x and y intercepts (see tomorrow’s stuff).
Day 40 (Tuesday, October 24)
Chapter 4 Test