# Derive the Formula for the Sum of a Finite Geometric Series

Standard A.SSE.4 – Derive the formula for the sum of a finite geometric series (when the common ratio is not 1), and use the formula to solve problems. For example, calculate mortgage payments.*

Vocabulary for this standard:
EngageNY lesson link – This appears in the Algebra II section of EngageNY and is not an area of emphasis for Ohio
Quick thoughts:
A base is a number or expression being multiplied in an exponent
An exponent is a number that describes how many times to use the number in a multiplication.
A coefficient is a number used to multiply a variable.
A negative exponent expresses that the base is the denominator of a fraction instead of the numerator
The multiplicative property of exponents says that when you multiply powers with the same base you just have to add the exponents
The division property of exponents says that when you divide powers with the same base you just have to subtract the exponents
The power of a power property says that when you raise an exponent to another power, you just have to multiply the exponents
Vocab
• Kahoot
• Quizizz
• Quizlet
Instruction:
• Desmos
Drills:
• Quizizz
• Kahoot
• Formative