Addition and subtraction equations up to 20: true or false?

Learning Objectives Define what an equation is and distinguish it from an expression. Evaluate numerical expressions involving addition and subtraction up to 20. Determine if a given addition or subtraction equation up to 20 is true or false. Justify their reasoning for classifying an equation as true or false. Identify and correct errors in determining the truth value of simple equations. Apply the concept of equality to verify mathematical statements. Understand the importance of evaluating both sides of an equation independently. Have you ever seen a math problem and wondered, 'Is that statement actually correct?' 🤔 Today, we'll become math detectives, investigating if simple addition and subtraction equations are true or false! In this lesson, we will...

TermDefinitionExample EquationA mathematical statement that shows two expressions are equal, connected by an equals sign (=).$$5 + 3 = 8$$ is an equation. ExpressionA combination of numbers, variables, and operation symbols, but without an equals sign.$$5 + 3$$ is an expression. $$8$$ is also an expression. EqualityThe state of being equal in value, represented by the equals sign (=). It means both sides of the equation have the same value.In $$10 - 2 = 8$$, the equality holds because both sides simplify to 8. InequalityA mathematical statement that shows two expressions are not equal, using symbols like $$\neq$$ (not equal to), $$<$$ (less than), $$>$$ (greater than), $$\le$$ (less than or equal to), or $$\ge$$ (greater than or equal to).$$5 + 2 \neq 8$$ is an inequality. $$5 + 2 &...

Rule for Evaluating Expressions To find the value of an expression, perform the indicated operations following the order of operations (Parentheses first, then Addition/Subtraction from left to right). This rule is fundamental for simplifying each side of an equation before comparing them. For expressions up to 20, this primarily means performing addition or subtraction within any grouping symbols first, then any remaining operations. Rule for Determining Truth Value of an Equation An equation $A = B$ is TRUE if and only if the numerical value of expression $A$ is equal to the numerical value of expression $B$. Otherwise, the equation is FALSE. This is the core principle for checking equations. You must evaluate both sides of the equals sign independently and then compare th...