Operations Flashcards
(20 cards)
Reasonableness of results
Always estimate or check: “Does this answer fit the situation?”
Concrete vs. Graphic vs. Verbal vs. Symbolic
Four ways to present the same math idea to deepen understanding.
Number Line
Straight line, equal spacing; hops show ±, ×, ÷. Left = less, Right = greater.
Commutative Property
Order doesn’t change the answer (addition, multiplication).
Associative Property
Grouping doesn’t change the answer (addition, multiplication).
Distributive Property
a(b + c) = ab + ac; breaks multiplication over addition/subtraction.
Additive Identity
0 keeps a number the same when added.
Multiplicative Identity
1 keeps a number the same when multiplied.
Additive Inverse
Opposite numbers sum to 0.
Multiplicative Inverse
Reciprocal multiplies to 1 (except 0).
Fact Family
Set of related +/− or ×/÷ facts using the same three numbers.
Lattice Multiplication
Grid with diagonals; write partial products, add along diagonals.
Area/Box Model
Rectangle split by place value; multiply or divide section by section.
PEMDAS
Order of operations: Parentheses, Exponents, Multiply/Divide, Add/Subtract.
Rectangular Array
Rows × columns model multiplication; count all items for the product.
Strip Diagram (Bar Model)
Bar divided into equal parts to visualize factors and products.
Key-word clue for multiplication
“Times,” “product of,” “area,” “twice,” “triple.”
Expression vs. Equation
Expression = no “=”; Equation = has “=”.
Inverse Operations
Use the opposite operation (+ ↔ −, × ↔ ÷) to solve or check.
Opposite Change Rule (addition)
Add to one addend to make a friendly number, subtract same from the other.
