NB TCN Numeracy flashcards
NB TCN Numeracy · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Place value
- The value of a digit determined by its position; each place is ten times the value of the place to its right, as in 0.1, 0.01, and 0.001.
- Order of operations
- The agreed sequence for evaluating expressions: parentheses first, then exponents, then multiplication and division left to right, then addition and subtraction left to right.
- Prime number
- A whole number greater than 1 whose only positive factors are 1 and itself. Examples include 2, 3, 5, 7, and 11; 1 is not prime.
- Absolute value
- The distance of a number from zero on the number line, always nonnegative. For example, the absolute value of negative seven is seven.
- Rounding rule
- To round to a given place, inspect the digit one place to its right: if it is 5 or greater, increase the target digit by one; otherwise leave it unchanged.
- Metric prefixes
- Prefixes scaling base units by powers of ten: kilo means 1000, centi means one hundredth, and milli means one thousandth of the base unit.
- Customary length units
- Relationships among common United States length units: 12 inches in a foot, 3 feet in a yard, and 5280 feet in a mile.
- Unit conversion by cancellation
- Multiply by a conversion fraction equal to one, placing the unwanted unit in the denominator so it cancels and only the desired unit remains.
- Celsius to Fahrenheit
- Convert Celsius temperature to Fahrenheit by multiplying the Celsius value by nine fifths and then adding thirty-two to the result.
- Volume of a prism
- For a rectangular prism, multiply length by width by height. The answer is expressed in cubic units because three lengths are multiplied.
- Proportion
- An equation stating that two ratios are equal, written a over b equals c over d. Solve it by cross-multiplying to get ad equals bc.
- Unit rate
- A rate expressed per single unit, found by dividing the quantity by the number of units. A unit price is cost divided by item count.
- Percent as decimal
- A percent is a fraction with denominator 100, so dividing by 100 converts it to a decimal. For example, 35 percent equals 0.35.
- Percent change
- Subtract the original value from the new value, divide that difference by the original value, then multiply by 100 to express the result as a percent.
- Successive percent changes
- Consecutive percent changes are applied by multiplying their decimal factors, not by adding the percents. A 20 percent rise then fall leaves 96 percent.
- Mean and median
- The mean is the sum of values divided by the count. The median is the middle value of an ordered list, or the average of the two middle values.
- Mode and range
- The mode is the most frequent value in a data set. The range is the maximum value minus the minimum value, describing total spread.
- Effect of outliers
- Extreme values shift the mean substantially but affect the median only slightly, so the median better represents a skewed data set's center.
- Circle graph sectors
- Each sector of a circle graph represents a category's share of the whole. Its central angle equals the category percent multiplied by 360 degrees.
- Simple probability
- The probability of an event equals the number of favorable outcomes divided by the total number of equally likely outcomes, giving a value from 0 to 1.
- Distributive property
- Multiplying a sum by a factor gives the same result as multiplying each addend by that factor and adding, written a times the sum of b and c equals ab plus ac.
- Combining like terms
- Terms with identical variable parts can be added or subtracted by combining their coefficients, so three x plus five x equals eight x.
- Slope formula
- The slope of a line through two points is the change in y divided by the change in x, equivalent to rise over run between the points.
- Slope-intercept form
- The equation y equals mx plus b describes a line with slope m and y-intercept b, the point where the line crosses the vertical axis.
- Arithmetic sequence rule
- In a sequence with constant difference d, each term increases by d. The nth term equals the first term plus the product of n minus one and d.
- Triangle angle sum
- The three interior angles of any triangle always add to 180 degrees, which allows a missing angle to be found from the other two.
- Supplementary and complementary
- Supplementary angles sum to 180 degrees, as on a straight line. Complementary angles sum to 90 degrees, forming a right angle together.
- Circle formulas
- For a circle of radius r, the area equals pi times r squared, and the circumference equals two times pi times r.
- Pythagorean theorem
- In a right triangle, the squares of the two leg lengths add to the square of the hypotenuse, the side opposite the right angle.
- Similar figure scaling
- Similar figures have equal corresponding angles and proportional sides. A scale factor k multiplies lengths, its square multiplies areas, and its cube multiplies volumes.
- Average speed
- Average speed equals total distance traveled divided by total elapsed time. It is not the simple average of the speeds used on separate segments.
- Combined work rate
- When workers or machines operate together, add their individual rates. The time needed together equals one divided by the combined rate.