Sixth Grade
Adding and subtracting decimals. Remember, when you are adding or subtracting decimals, the most important thing is to line up the decimal points. By doing this, you are also lining up the numbers in their proper place values. Once you've done that, add zeros in all the empty places and then add or subtract as normal. Bring the decimal straight down into the answer. Also, when you have a whole number like 32, you will put the decimal point to the RIGHT of the number. For example:
32 changes to 32.
You could then add extra zeros after the decimal point. If you were subtracting 32 - 0.75, you would write it like this:
32.00
- 0.75
You'd then be able to subtract by crossing out the zeros and borrowing from the 2.
The assignment is the homework page, #1-22.
Seventh Grade
Math - Proportions Worksheet. On the first 6, you are checking to see if the two ratios form a proportion. To do this, you use cross products. So, if you had 5/6 and 10/12, you would check to see if it was proportional by multiplying 12 x 5 and 6 x 10. Since both of them equal 60, the two ratios are proportional.
When you are missing a number, you will still use cross products. For example, if you had
2/5 = b/15, you would cross multiply the two you can, the 2 x 15 and then divide that by 5.
2 x 15 = 30 divided by 5 = 6. So b = 6.
That was easy because you can tell using equivalent fractions. Sometimes the answer will be a mixed number though.
3/10 = 7/m
Here, you multiply 7 x 10 and divide by 3. 7 x 10 = 70 divided by 3 = 23 1/3
Write the remainder as a fraction.
Geography - Answer all the questions in the Activity Atlas on pages 162-167.
Eighth Grade
Pre-Algebra: We made prisms on Friday for use in figuring out surface area. We will continue on Monday. No homework!
Algebra I: Coin and Value problems. Remember, you are using substitution to solve these. First, determine the COUNT statement. How many of each thing do you have? How many quarters? How many dimes? How many tickets of each type? Then determine the VALUE statement. How much is each thing worth? What is the value of all the things?
Here is an example: Tommy had 35 nickels and dimes whose value was $2.75. How many of each type of coin did he have?
COUNT statement: He had 35 nickels and dimes. That means that all the nickels and dimes added up to 35. So, use the variables n and d for nickels and dimes:
n + d = 35
Value statement: The value was $2.75. Since each nickel is 5 cents and each dime is 10 cents, you would write it like this:
5n + 10d = 275
We took out the decimal points to make it easier. We put 5 in front of n, because the n stood for the NUMBER of nickels, so the value all of the nickels would be 5 times that number, 5n.
Now, we need to use substitution to solve. First, rearrange the COUNT statement so that you have what just n equals or just d equals. I'm going to move the d to the right side so I get what just n equals.
n = 35 - d
Now I can substitute that in for n in the value statement:
5(35-d) + 10d = 275
175 - 5d + 10d = 275
175 +5d = 275
5d = 100
d = 20
There are 20 dimes and that means that there are 15 nickels. Remember, the number of dimes AND nickels equaled 35, so I just subtracted 20 from 35 to get the number of nickels.
PLEASE email me if you need help setting up an equation!
See you Monday,
Mrs. Swickey
