Grade 7 Mathematics flashcards
Grade 7 Mathematics · Build recall with a focused review session.
33 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Unit rate
- A rate rewritten so the second quantity is exactly 1, found by dividing. If 5 notebooks cost 12 dollars, the unit rate is 2.40 dollars per notebook.
- Constant of proportionality
- The fixed ratio k in y = kx, equal to y divided by x for every corresponding pair. It is also the slope of the line through the origin.
- Proportion
- An equation stating that two ratios are equal, such as 3/4 = 9/12. Cross-multiplying gives equal products and lets you solve for an unknown.
- Percent change
- The original value divided into the amount of change, written as a percent. Subtract the original from the new value, divide by the original, then multiply by 100.
- Scale factor
- The ratio of a length in a scale drawing to the matching length in the real object. Multiply an actual measure by it to get the drawing measure.
- Better buy
- The item with the lower cost per single unit. Divide total price by the number of units for each option, then compare the resulting unit prices.
- Rational number
- Any number writable as p/q where p and q are integers and q is not zero. It includes integers, fractions, and terminating or repeating decimals.
- Additive inverse
- The opposite of a number, which sums with it to zero. For example, the additive inverse of -8 is 8, because -8 + 8 = 0.
- Absolute value
- A number's distance from zero on the number line, always nonnegative. Both 6 and -6 have an absolute value of 6.
- Terminating decimal
- A decimal that ends after a finite number of digits. A reduced fraction converts to one only when its denominator has no prime factors besides 2 and 5.
- Repeating decimal
- A decimal in which a digit or block of digits repeats forever, shown with a bar. It is always a rational number and can be rewritten as a fraction.
- Reciprocal
- The number you multiply by to get 1, formed by flipping numerator and denominator. Dividing by a fraction means multiplying by its reciprocal.
- Integer subtraction rule
- Subtracting an integer is the same as adding its opposite. So 4 - (-9) becomes 4 + 9, which equals 13.
- Like terms
- Terms with exactly the same variable part, including exponents. Only like terms can be combined, so 7x and 2x combine but 7x and 2x squared do not.
- Distributive property
- Multiplying a factor by a sum means multiplying it by each addend and adding. In symbols, a(b + c) = ab + ac.
- Coefficient
- The number multiplying a variable in a term. In -5x the coefficient is -5, and it tells you the size and sign of that term.
- Two-step equation
- An equation needing two inverse operations to isolate the variable, such as 3x + 5 = 20. Subtract 5, then divide by 3.
- Inequality sign reversal
- Multiplying or dividing both sides of an inequality by a negative number flips the inequality symbol. Dividing -3x > 12 by -3 gives x < -4.
- Linear expression
- An expression whose variable terms are all first powers, with no variables multiplied together or in denominators. An example is 4x - 7.
- Greatest common factor
- The largest factor shared by all terms of an expression. Factoring it out rewrites 15x + 25 as 5(3x + 5).
- Circumference
- The distance around a circle, computed as pi times the diameter or twice pi times the radius. For radius 5, it is about 31.4 units.
- Area of a circle
- The space inside a circle, found by multiplying pi by the square of the radius. A circle of radius 3 has area about 28.3 square units.
- Triangle area
- Half the product of a base and the height perpendicular to it. A triangle with base 10 and height 6 has area 30 square units.
- Prism volume
- The base area multiplied by the height of the solid. For a rectangular prism measuring 2 by 3 by 4, the volume is 24 cubic units.
- Surface area
- The total area of all outer faces of a solid, measured in square units. It is the sum of each face's area, counted once.
- Supplementary angles
- Two angles whose measures add to 180 degrees. If one angle measures 115 degrees, its supplement measures 65 degrees.
- Vertical angles
- The pair of opposite angles formed by two intersecting lines. They are always equal in measure and share only a vertex.
- Mean
- The sum of all data values divided by how many values there are. Adding an extreme outlier shifts the mean more than the median.
- Median
- The middle value when data are ordered from least to greatest. With an even count, average the two middle values.
- Mean absolute deviation
- The average distance of data values from the mean. A larger value means the data are more spread out around the center.
- Random sample
- A subset chosen so every member of the population has an equal chance of selection, which makes results more representative of the whole group.
- Complement rule
- The probability that an event does not happen equals 1 minus the probability that it does. If rain chance is 0.3, no rain is 0.7.
- Independent events
- Events whose outcomes do not affect each other. Their combined probability is the product of the separate probabilities.