OST Grade 3 Math flashcards
OST Grade 3 Math · 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.
- Product
- The answer to a multiplication problem. In 4 × 6 = 24, the product is 24. It names the total when you join equal groups.
- Factor
- A number being multiplied in a multiplication problem. In 3 × 7 = 21, both 3 and 7 are factors. A missing factor is found by dividing.
- Quotient
- The answer to a division problem. In 24 ÷ 6 = 4, the quotient is 4. It tells how many groups of 6 fit into 24.
- Remainder
- The amount left over after dividing into whole groups. In 25 ÷ 4 = 6 R1, the remainder is 1, and it is always less than the divisor.
- Commutative property of multiplication
- Changing the order of factors does not change the product: 7 × 3 = 3 × 7 = 21. This property works for multiplication and addition, not subtraction or division.
- Distributive property
- A product can be split into smaller products and added: 6 × 14 = 6 × (10 + 4) = 60 + 24 = 84. This makes multiplying two-digit numbers easier.
- Unknown factor
- The missing number in a multiplication sentence such as 8 × ? = 56. Divide the product by the known factor: 56 ÷ 8 = 7, so the unknown factor is 7.
- Place value
- The value a digit has because of its position. In 5,382 the 3 is worth 300 and the 8 is worth 80, because each place is ten times the place to its right.
- Expanded form
- A number written as the sum of its place values. 4,706 in expanded form is 4,000 + 700 + 0 + 6. It shows what each digit is worth.
- Rounding to nearest hundred
- Look at the tens digit. If it is 5 or more, round up; if 4 or less, keep the hundreds digit. Then write zeros for tens and ones: 3,472 rounds to 3,500.
- Regrouping
- Trading 10 ones for 1 ten, or borrowing 1 ten as 10 ones, when adding or subtracting. It keeps each column correct when a column reaches 10 or is too small.
- Comparing multi-digit numbers
- Start at the leftmost digit and compare place by place. The first place where digits differ decides: 4,285 > 4,258 because 8 tens is more than 5 tens.
- Multiplying by 10 and 100
- Multiplying a whole number by 10 adds one zero (10 × 36 = 360); multiplying by 100 adds two zeros (100 × 36 = 3,600). Each zero shifts digits one place left.
- Division with remainders
- Divide as far as possible, then the leftover is the remainder. 25 ÷ 4 = 6 R1 because 4 × 6 = 24 and 25 − 24 = 1. The remainder is less than the divisor.
- Unit fraction
- A fraction with numerator 1, such as 1/2, 1/3, or 1/8. It is one equal part of a whole that has been split into the denominator's number of parts.
- Equivalent fractions
- Fractions that name the same amount and sit at the same point on a number line. Multiply numerator and denominator by the same number: 2/3 = 4/6 = 6/9.
- Comparing fractions, same numerator
- When numerators match, the fraction with the smaller denominator is larger, because the whole is cut into fewer, bigger pieces. So 3/4 > 3/8.
- Common denominator
- A shared denominator used to compare or compute fractions. Rewrite 2/3 and 3/5 as 10/15 and 9/15; then compare numerators: 10/15 > 9/15.
- Fraction equal to one
- A fraction whose numerator equals its denominator, such as 4/4 or 7/7. It names exactly one whole. Its point on the number line is 1.
- Mixed number
- A whole number plus a fraction, such as 2 1/3. It names an amount greater than 1. The fraction 7/3 equals the mixed number 2 1/3.
- Adding fractions, same denominator
- Keep the denominator and add the numerators: 2/5 + 1/5 = 3/5. The denominator names the size of the pieces and does not change when you join pieces.
- Whole number as a fraction
- Any whole number can be written over 1 or as an equivalent fraction: 3 = 3/1 = 6/2 = 9/3. All of these sit at the same point, 3, on a number line.
- Elapsed time
- The time between a start and an end. Subtract, regrouping 1 hour as 60 minutes: from 3:40 to 5:10 is 1 hour 30 minutes.
- Kilogram and gram
- Metric units of mass. 1 kilogram = 1,000 grams. A paper clip has a mass of about 1 gram; a kilogram is about the mass of a textbook.
- Liter and milliliter
- Metric units of liquid volume. 1 liter = 1,000 milliliters. A liter is about a large water bottle; a teaspoon holds about 5 milliliters.
- Picture graph scale
- The number each symbol stands for. If one star means 5 books, then 4 stars mean 20 books. Always read the key before comparing categories.
- Line plot
- A number line with an X above each data value. Each X is one item. Values with more Xs are more common; compare counts by subtracting the Xs.
- Area of a rectangle
- Multiply length by width. A rectangle 6 units by 4 units has area 6 × 4 = 24 square units. Area counts the unit squares that cover the shape.
- Perimeter
- The distance around a shape: add all side lengths. A rectangle's perimeter is 2 × (length + width); a square's is 4 × side.
- Quadrilateral
- A polygon with 4 sides and 4 angles. Squares, rectangles, rhombuses, parallelograms, and trapezoids are all quadrilaterals.
- Square
- A quadrilateral with 4 equal sides and 4 right angles. Every square is also a rectangle and a rhombus, but not every rectangle is a square.
- Equal shares
- Parts of a shape that have the same area. If a shape is cut into 4 equal shares and 3 are shaded, the shaded part is 3/4 of the whole.