OST Grade 4 Math key terms

The result you get when you multiply two or more numbers together. For example, in 6 × 7 = 42, the number 42 is the product.

A number that is multiplied by another number to make a product. In 4 × 5 = 20, both 4 and 5 are factors of 20.

The answer to a division problem, showing how many times one number fits into another. In 24 ÷ 6 = 4, the quotient is 4.

The number being divided in a division problem. In 35 ÷ 5 = 7, the dividend is 35, the amount being split into equal groups.

The number you divide by, telling how many equal groups you are making or how many are in each group. In 35 ÷ 5 = 7, the divisor is 5.

The amount left over when a number cannot be divided evenly. Dividing 17 by 5 gives 3 with a remainder of 2.

A number you get by multiplying a given number by whole numbers. Multiples of 4 include 4, 8, 12, 16, and 20.

A whole number greater than 1 that has exactly two factors: 1 and itself. Examples include 2, 3, 5, 7, and 11.

A whole number greater than 1 that has more than two factors. For instance, 12 is composite because 1, 2, 3, 4, 6, and 12 all divide it evenly.

Comparing two amounts by asking how many times as many one is than the other. Saying 15 is 3 times as many as 5 is a multiplicative comparison.

A number sentence with an equals sign showing that two expressions have the same value. For example, 8 × 3 = 24 is an equation.

A letter or symbol that stands for an unknown number in an equation or expression. In n + 7 = 15, the letter n is the variable.

A combination of numbers, operation signs, and sometimes letters that does not include an equals sign. Examples are 5 + 3 and 4 × n.

The agreed rules for which part of a number sentence to compute first. Do work in parentheses first, then multiplication and division, then addition and subtraction.

Curved grouping symbols ( ) that show which operation to do first in an expression. In (2 + 3) × 4, add first to get 5, then multiply.

The value a digit has because of the position it holds in a number. In 4,382, the 3 stands for 3 hundreds, or 300.

The usual way of writing a number using digits only. The number three thousand forty-seven written in standard form is 3,047.

Writing a number as the sum of the values of each of its digits. For example, 5,206 in expanded form is 5,000 + 200 + 6.

Writing a number using English words instead of digits. The number 912 written in word form is nine hundred twelve.

Replacing a number with a nearby number of a certain place value to make it easier to work with. 47 rounded to the nearest ten is 50.

A reasonable answer found by rounding or using friendly numbers instead of computing exactly. Estimating 198 + 305 as 200 + 300 gives about 500.

The result of adding two or more numbers. In 12 + 8 = 20, the sum is 20.

The result of subtracting one number from another. In 15 − 9 = 6, the difference is 6.

The smaller products you get by breaking a multiplication problem into place-value parts. For 23 × 4, the partial products are 80 and 12.

A number that names part of a whole or part of a set, written as a numerator over a denominator. The fraction 3/4 means 3 of 4 equal parts.

The top number of a fraction, which tells how many equal parts are being described. In 5/8, the numerator is 5.

The bottom number of a fraction, which tells how many equal parts the whole is divided into. In 5/8, the denominator is 8.

Different fractions that name the same amount. For example, 1/2, 2/4, and 4/8 are equivalent because they cover the same part of a whole.

A fraction written with the smallest possible whole-number numerator and denominator. The fraction 6/8 in simplest form is 3/4.

A shared denominator that two or more fractions can be rewritten with so they can be compared or added. For 1/3 and 1/4, a common denominator is 12.

A number made of a whole number and a fraction together. For example, 2 1/3 means two wholes plus one third.

A fraction whose numerator is greater than or equal to its denominator, so it names one whole or more. For example, 7/4 equals 1 3/4.

A way of writing a number using place value based on tenths, hundredths, and so on, with a decimal point. The decimal 0.25 equals the fraction 25/100.

A fraction with a numerator of 1, such as 1/2, 1/5, or 1/10. Any fraction can be built by combining copies of unit fractions.

The amount of flat surface a shape covers, measured in square units. A rectangle 4 units by 6 units has an area of 24 square units.

The distance all the way around the outside edge of a shape, found by adding the lengths of its sides. A 3-by-5 rectangle has a perimeter of 16 units.

A square that is one unit long on each side, used to measure area. A shape covered by 12 such squares has an area of 12 square units.

A number line marked with an X or dot above a value each time that value appears in a data set, showing how often each amount occurs.

The figure formed by two rays that share a common endpoint, measured in degrees. A right angle measures exactly 90 degrees.

An angle that measures exactly 90 degrees, often shown with a small square mark. The corners of a rectangle are right angles.

The unit used to measure the size of an angle. A full turn is 360 degrees, so a right angle is 90 degrees.

A line that divides a figure into two halves that are mirror images of each other. A square has four lines of symmetry.

Lines in the same plane that never cross, no matter how far they are extended. The opposite sides of a rectangle are parallel.

Two lines that meet or cross to form a right angle. The adjacent sides of a square are perpendicular.

A closed flat shape with exactly four straight sides and four angles. Squares, rectangles, and trapezoids are all quadrilaterals.