Balance subtraction equations - up to 18

Learning Objectives Define a subtraction equation and identify its components, including the variable. Explain the concept of 'balancing' an equation and why it's crucial for finding solutions. Apply the inverse operation of addition to solve one-variable subtraction equations. Accurately solve subtraction equations where the unknown is the minuend or subtrahend, with numbers up to 18. Check their solutions by substituting the found value back into the original equation. Confidently solve real-world problems that can be modeled by subtraction equations up to 18. Imagine you have a scale ⚖️, and both sides must always weigh the same. What happens if you add weight to only one side? In this lesson, we'll learn how to keep mathematical equations balanced wh...

TermDefinitionExample EquationA mathematical statement that shows two expressions are equal, usually separated by an equals sign (=).$x - 5 = 10$ VariableA letter (like $x$, $y$, or $a$) that represents an unknown number in an equation.In $x - 3 = 7$, $x$ is the variable. Inverse OperationsOperations that 'undo' each other. Addition is the inverse of subtraction, and subtraction is the inverse of addition.To undo subtracting 5, you add 5. BalanceThe principle that both sides of an equation must always remain equal. Whatever operation you perform on one side, you must perform on the other.If you add 3 to the left side of an equation, you must also add 3 to the right side to keep it balanced. SolutionThe value of the variable that makes the equation true.For $x - 2 = 8$, the solut...

The Rule of Balance If $A = B$, then $A + C = B + C$ and $A - C = B - C$. To keep an equation balanced, any operation (addition, subtraction, multiplication, division) performed on one side of the equals sign must also be performed on the other side. Inverse Operation for Subtraction To isolate a variable that is being subtracted from, use addition. To isolate a variable that is subtracting another number, use addition. If you have an equation like $x - a = b$, you add $a$ to both sides. If you have $a - x = b$, you first add $x$ to both sides, then subtract $b$ from both sides.