The short version A meter is about 39.37 inches, or roughly 3 feet 3 inches. That makes it a little longer than a yard. One meter equals 100 centimeters and 1,000 millimeters. It takes 1,000 meters to make a kilometer. For a quick mental picture: a meter is about the height of a kitchen counter…
The short version 2D shapes are flat shapes with only two dimensions, length and width. They have area and perimeter but no volume. Most 2D shapes kids learn are polygons: closed shapes made of straight sides, named by how many sides they have (triangle 3, quadrilateral 4, pentagon 5, hexagon 6, octagon 8). Circles, ovals…
The short version The difference in math is the answer to a subtraction problem. In 10 – 4 = 6, the difference is 6. “Find the difference between two numbers” means subtract the smaller from the larger. It tells you how far apart the numbers are. You can find a difference by taking away or…
The short version A terminating decimal is a decimal that ends. It has a fixed number of digits after the decimal point, like 0.5, 3.25 or 0.0625. A fraction becomes a terminating decimal only if, once it’s in lowest terms, its denominator has no prime factors other than 2 and 5. Always simplify first. 3/6…
The short version The identity property of addition says that adding 0 to any number leaves the number unchanged: a + 0 = a. That’s why 0 is called the additive identity. The identity property of multiplication says multiplying any number by 1 leaves it unchanged: a × 1 = a. That makes 1 the…
The short version Length is usually the longer side of a rectangle, and width is the shorter side. Height is how tall something is, measured straight up from the base. A flat shape only has two dimensions (length and width). A solid like a box adds a third: height. Box sizes are usually written L…
The short version Math properties are rules that are always true for numbers, like “you can add in any order.” They let you rearrange a problem without changing the answer. The big ones are commutative (order), associative (grouping), distributive (multiplying across a sum), identity (adding 0 or multiplying by 1) and inverse (undoing an operation…
The short version In a decimal place value chart, the places to the right of the decimal point are tenths, hundredths, thousandths, ten-thousandths and so on. There’s no “oneths.” Each place is worth 10 times the place to its right. So 0.1 is ten times 0.01. Read the decimal point as “and,” then name the…
The short version An improper fraction has a numerator (top number) that’s equal to or bigger than its denominator (bottom number), like 7/4 or 5/5. Its value is 1 or more. To turn an improper fraction into a mixed number, divide: 17/5 is 17 ÷ 5 = 3 remainder 2, so 3 2/5. To go…
The short version The transitive property says that if a = b and b = c, then a = c. Two things equal to the same thing are equal to each other. It also works for inequalities that point the same way: if a < b and b < c, then a < c. In…