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Add/Subtract Mixed Numbers Find LCD then +/- Fractions +/- Whole Numbers Simplify. Convert a fraction to a % Multiply by 100 and use % symbol. Convert a fraction to a decimal Divide numerator by denominator. L. a. 0.75__. L os =. b. ¾ =. Subtract Mixed Numbers w/Borrowing
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Add/Subtract Mixed Numbers • Find LCD then +/- Fractions • +/- Whole Numbers • Simplify • Convert a fraction to a % • Multiply by 100 and use % symbol Convert a fraction to a decimal Divide numerator by denominator. L a 0.75__ Los = b ¾ = • Subtract Mixed Numbers w/Borrowing • Find LCD • Rename by Whole # then subtract • Simplify -2 8 20 -20 0 • Multiply Fractions • Numerator x numerator • Denominator x denominator • Simplify • Convert a decimal to a % • Move decimal to right twice or x by 100 • 0.8 = 80% • Convert a decimal to a fraction • Use the last digit of the decimal. • Convert a % to a decimal • Move decimal to left twice or divide by 100 • 80% = 0.8 0.abcd • Apply to place value fraction. • Always simplify if possible. • Divide Fractions • Flip divisor • numerator x numerator • denominator x denominator • Simplify • Simplify fractions (Repeat the process) • Divide the numerator and denominator by the same number. • Order/Compare Fractions Decimals %’s • Convert all values into fractions, decimals, or %’s • Then order or compare Convert a mixed # to an improper fraction. Order from greatest to least. • Convert an improper fraction to a mixed #. • Divide the numerator by the denominator. • Add/Subtract Fractions • Find LCD then +/- numerators • keep like denominator • Rounding Numbers • Always look to the right of your rounding digit • If the digit is 0,1,2,3 or 4 do not change the rounding digit. • All digits that are on the right hand side of the requested rounding digit will become 0 • Determine what your rounding digit is and look to the right of it. If the digit is 5,6,7, 8 or 9, your rounding digit rounds up by one number. All digits that are on the right hand side of the requested rounding digit will become 0 -(Axc) b -20 3 Round nearest dollar 16.8 = $17 Round nearest Penny 1.652 = $1.65
Square Roots • The square root of a number, n, written below is the number that gives n when multiplied by itself.+/- Whole Numbers • Finding the square root of a number is the inverse operation of squaring that number. Remember, the square of a number is that number times itself. • Add/Subtract Decimals • Line up decimals • Add/Subtract • Divide with decimal divisors • If the divisor is not a whole number, move decimal point to right to make it a whole number and move decimal point in dividend the same number of places. • Put decimal point directly above decimal point in the dividend. • Divide as usual 12.3 +5.8 • Multiply Decimals • Line up the numbers on the right - do not align the decimal points. • Multiply • Place the decimal point in the answer by starting at the right and moving a number of places equal to the sum of the decimal places in both numbers multiplied. • Order/Compare decimals • Line up decimals • Then compare/order > Greater than or < Less than 12.3 5.82 12.3 05.8 12.3 5.82 > Exponents • Divide decimals (dividends) • Put decimal point directly above decimal point in the dividend. • Divide as usual • Scientific Notation • Def. product of two factors where: • 1st factor: 1 or more but less than 10 • 2nd factor: a power of 10. • Order of Operations PEMDAS • () 1st • Exponents 2nd • Multiply & Divide Left to right • Add/ decimal point in the dividend. • Divide as usual Write in scientific notation and vice versa.
Integers Percents = means per hundred ¾ = 75% 2/3 = 662/3% ½ = 50% 1/3 = 33 1/3% ¼ = 25% 1/5 =20% 1/6 =16 2/3% 1/7 = 14% 1/8 =12.5% 1/10 = 10% Find popular %’s (drop % sign) 75% times by ¾ or times by 0.75 50% divide by 2 or times by 0.5 33 1/3% divide by 3 25% divide by 4 or times by 0.25 20% divide by 5 or times by 0.2 10% divide by 10, times by 0.1, move left decimal once 1% divide by 100 or times by 0.01 or move decimal left twice • Find the sale price • Find the % of original (discount) • Subtract discount from the original (sale price) • Shirt reg. $16 for 20% off (convert 20% to a decimal & multiply) • 20% of 16 = 3.20 (discount) • 16-3.20 = $12.80 (sale price) • Find the discount rate • original/regular – sale (discount) • Discount divided by original times 100 • Shirt regular $20 on sale $12 • An integer is a whole number that can be either greater than 0, called positive, or less than 0, called negative. Zero is neither positive nor negative. • Two integers that are the same distance from zero in opposite directions are called opposites. • Every integer on the number line has an absolute value, which is its distance from zero. Add/Subtract Integers Proportions A proportion is a statement where two ratios are equal. It can be written in two ways: • Use the number line for adding and subtracting integers: • Add a positive integer by moving to the right on the number line • Add a negative integer by moving to the left on the number line • Subtract an integer by adding its opposite • Find the regular price • 100% - n% Off (%paid) • Sale price x 100 • answer divided by %paid (regular price) • Sale price $15 at 20%off • 100-20=80(80%paid) • 15x100=1500 • 1500/80=18.75 =>$18.75 = regular price • Find the Percent of a number • Convert % to a decimal • Multiply the decimal by the number • 16% of 50 = 0.16 x 50 = 8 • Using the Percent Equation • identify each component of the equation • “is” part of the whole or the result • “of” is the total or original amount • “%” is the percent(always over 100) • 17 is what percent of 51? • Add Integers Rule • Same sign: add & keep sign -8+-5 = -13 • Different signs: Subtract & keep sign of largest absolute value. – 8 + 5 = -3 • Find % off • Find the % of the original (discount) • Subtract discount from original (sale) • Find % Mark Up • Find % of the original (profit) • Add profit to original • Subtract Integers Rule • To subtract a number, add its opposite. • Leave Change Change /KFC • -8-5 = -8+-5 Keep Flip Change • = -13 Change= 2 • Multiply/Divide Integers • Same signs: multiply/divide as usual answer is positive • Different signs: multiply/divide as usual answer is negative • -4 x -3 = 12 -8/2 = - 4 Original =10 New = 12 • Percent of change • Find the difference of original and new • Divide the difference by the original • Multiply by 100 • Raise from $10/hr to $12/hr • 20% increase
1 1 2 2 3 3 Trigger Words In Word Problems Circumference Around a circle Perimeter Around the Base Area Cover a Base figure Lateral Surface Area Cover sides of a 3D figure Total Surface Area Cover all of a 3D figure Volume Fill a 3D figure P represents the perimeter of the base shape of a 3D figure. B represents the area of the Base of a 3D figure. ¾ ¼ 1¼ 1¾ 2¼ 2¾ 1½ 2½ ½ Inch Ruler 0.1 0.2 0.3 0.4 0.6 0.7 0.8 0.9 1.1 1.2 1.3 1.4 1.6 1.8 1.7 1.9 0.5 1.5 2.1 2.2 2.3 2.4 2.6 2.8 2.9 2.7 2.5 ½ Centimeter Ruler
Venn Diagram Simple Probability Ways they’re the same 20 Marbles: 5 red, 6green, 9 blue Only about item 2 Only about item 1 Probability of Independent Events • Independent means with replacement • Find the probability of both events • Multiply the two events • Simplify if possible 20 Marbles: 5 red, 6green, 9 blue P (blue 1st ) then p(green 2nd) with replacement • Measures of Central Tendency & When To Use Them • Outliers – a data value that’s much higher or much lower than the other data values in a set • Mean – average (when you have no outliers) • Median – middle of an ordered set (when outliers influence the mean) • Mode –occurs the most (when data isn’t numerical) • Find the Measures of Central Tendency • Mean-Add each item, then divide the total by the # of items • Median-order the set, then choose the middle number. If there are two numbers, find their average • Mode-the number that occurs the most in a set of data (most popular) • Find the mean, median, & mode. Identify any outliers. • 27,32, 30,31,11,30 • Mean = 27+32+30+31+11+30 => estimate 26.8 • Median = 32, 31, 30, 30, 27, 11 • Mode = 30 • Outlier:11 Probability of Dependent Events This is a coordinate plane. It has two axes and four quadrants. The two number lines form the axes. The horizontal number line is called the x-axis and the vertical number line is called the y-axis. The center of the coordinate plane is called the origin. It has the coordinates of (0,0). Locations of points on the plane can be plotted when one coordinate from each of the axes are used. This set of x and y values are called ordered pairs. • Dependent means no replacement • Find the probability of 1st event • Find probability 2nd event after removing the item from the 1st event. • Multiply the two events • Simplify if possible Sequences 20 Marbles: 5 red, 6green, & 9 blue p(blue 1st ) then p(green 2nd) without replacement p(blue 1st ) then p(blue 2nd) without replacement Tables & Function Rules y = 3x - 1 Common difference (term) +/- Constant
Pythagorean Theorem REMEMBER: The Pythagorean Theorem ONLY works for Right Triangles! a, b are legs.c is the hypotenuse(c is across from the right angle). Example Finding Square Roots • Hypotenuse missing • Square given sides • Add squares • Find the square root Example A ramp was constructed to load a truck. If the ramp is 9 feet long and the horizontal distance from the bottom of the ramp to the truck is 7 feet, what is the vertical height of the ramp? • Leg missing • Square given sides • Subtract squares • Find the square root Perfect Squares About 6 ft
When is the TAKS? 8th Grade Math TAKS April 6, 2010 Score back April 27, 2010** 7th Grade LAT Math April 26, 2010 Scores Back May 19-26, 2010 7th Grade Math April 26, 2010 Scores Back May 19-26, 2010 8th Grade LAT Math May 17, 2010 Scores Back June 8, 2010*** 8th Grade Math TAKS Retest May 18, 2010 Scores Back June 8, 2010*** 8th Grade Math TAKS Retest June 29, 2010 Scores Back July 16, 2010 ** 10 working days after the testing contractor receives the scorable materials † Includes TAKS (Accommodated) only *** Tests administered over two days, May 18 and May 19 Math TAKS Blueprint