MCAS Math Grade 4 flashcards

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 based on its position in a number. In 5,306 the 5 means 5,000, the 3 means 300, and the 6 means 6 ones.

Standard form

A number written using digits only, such as 40,208. It differs from word form (forty thousand, two hundred eight) and expanded form (40,000 + 200 + 8).

Expanded form

A number broken apart by place value and written as a sum. For example, 6,451 = 6,000 + 400 + 50 + 1.

Rounding to a place

Replace a number with a nearby number at a given place. Check the digit to the right: 5 or more rounds up, 4 or less rounds down. 3,472 rounded to the nearest hundred is 3,500.

Comparing whole numbers

Compare digits from the leftmost place. The number with the greater digit in the first place where they differ is greater; 45,309 > 45,039 because 3 hundreds > 0 hundreds.

Partial products

A multiplication method that splits one factor by place value. For 23 × 14, compute 23 × 10 = 230 and 23 × 4 = 92, then add to get 322.

Remainder

The amount left over after dividing into equal whole groups. In 17 ÷ 5 = 3 remainder 2, the remainder 2 is always less than the divisor 5.

Factors and multiples

Factors divide a number evenly (factors of 12: 1, 2, 3, 4, 6, 12). Multiples are products with whole numbers (multiples of 4: 4, 8, 12, 16...).

Prime and composite

A prime number has exactly two factors, 1 and itself (2, 3, 5, 7, 11). A composite number has more than two factors (4, 6, 8, 9, 10).

Equivalent fractions

Different fractions that name the same amount. Multiply or divide numerator and denominator by the same nonzero number: 1/2 = 3/6 = 6/12.

Comparing fractions

With like denominators, the larger numerator is greater (5/8 > 3/8). With like numerators, the smaller denominator is greater (1/3 > 1/5).

Benchmark fraction 1/2

A reference for estimating fractions. A fraction equals 1/2 when the numerator is half the denominator; 3/8 is less than 1/2 and 5/8 is greater.

Decomposing fractions

Writing a fraction as a sum of smaller fractions with the same denominator. For example, 5/6 = 2/6 + 3/6, or 5/6 = 1/6 + 1/6 + 1/6 + 1/6 + 1/6.

Multiplying fraction by whole number

Add the fraction to itself that many times: 3 × 2/5 = 2/5 + 2/5 + 2/5 = 6/5. Multiply the whole number by the numerator and keep the denominator.

Adding mixed numbers

Add whole numbers and fractions separately, then regroup if the fraction sum is 1 or more. 2 3/4 + 1 3/4 = 3 6/4 = 4 2/4.

Tenths and hundredths

Decimal places to the right of the point. 0.7 = 7/10, 0.07 = 7/100, and 0.70 = 0.7 because 70/100 = 7/10.

Comparing decimals

Compare digits from left to right by place value. 0.6 > 0.58 because 6 tenths is greater than 5 tenths, even though 58 has more digits.

Metric length units

1 kilometer = 1,000 meters, 1 meter = 100 centimeters, 1 centimeter = 10 millimeters. Multiply when converting to a smaller unit, divide for a larger one.

Metric mass and capacity

1 kilogram = 1,000 grams and 1 liter = 1,000 milliliters. To change kilograms to grams, multiply by 1,000; to change milliliters to liters, divide by 1,000.

Elapsed time

The time between a start and an end. From 9:40 a.m. to 11:15 a.m. is 1 hour 35 minutes; count whole hours first, then remaining minutes.

Area of a rectangle

Area equals length times width, measured in square units. A 6 cm by 4 cm rectangle has area 24 square centimeters.

Perimeter

The distance around a figure, found by adding all side lengths. A rectangle's perimeter is 2 × (length + width).

Area of composite figure

Split the figure into non-overlapping rectangles, find each rectangle's area, then add the areas together to get the total.

Right angle

An angle measuring exactly 90 degrees, forming a square corner. A triangle with one right angle is a right triangle.

Acute and obtuse angles

An acute angle measures less than 90 degrees; an obtuse angle measures more than 90 degrees but less than 180 degrees.

Parallel lines

Lines in the same plane that never intersect and stay the same distance apart, like the top and bottom edges of a rectangle.

Perpendicular lines

Two lines that intersect and form a right angle, such as the vertical and horizontal sides of a square.

Line symmetry

A figure has line symmetry when a line can fold it into two matching halves. A square has 4 lines of symmetry; a non-square rectangle has 2.

Triangle side names

Equilateral has 3 equal sides, isosceles has at least 2 equal sides, and scalene has no equal sides. Every equilateral triangle is also isosceles.

Numerical pattern rule

The rule that produces each term from the previous one. In 5, 10, 20, 40 the rule is multiply by 2, so the next term is 80.

Line plot

A number line with an X above each value for every time it appears. It shows how data cluster and which value is most common.

Multi-step word problem

A problem needing more than one operation. Plan the steps, solve in order, and check that the answer matches the units requested.