Add four or more numbers up to two digits each

Learning Objectives Identify an arithmetic sequence from a list of four or more two-digit numbers. Determine the key components of an arithmetic sequence: the first term (a₁), the common difference (d), and the number of terms (n). Calculate the value of the nth term (aₙ) in an arithmetic sequence. Apply the formula for the sum of an arithmetic series (Sₙ) to efficiently add four or more numbers. Solve word problems that require finding the sum of a sequence of numbers. Verify the sum of a sequence using strategic pairing methods (Gaussian method). Ever tried to add all the numbers from 1 to 100 in your head? 🤔 A famous mathematician did it as a child in seconds! Let's learn his secret. This lesson moves beyond simple column addition. You will learn how to recognize p...

TermDefinitionExample SequenceAn ordered list of numbers, where each number is called a term.12, 15, 18, 21, 24 is a sequence. Arithmetic SequenceA sequence where the difference between consecutive terms is constant.In the sequence 10, 21, 32, 43, the difference is always 11. Common Difference (d)The constant value added to each term to get the next term in an arithmetic sequence.For the sequence 88, 81, 74, 67, the common difference (d) is -7. Term (aₙ)A specific number in a sequence. a₁ is the first term, a₂ is the second term, and aₙ is the nth (or last) term.In 15, 20, 25, 30, 35, the first term a₁ is 15 and the fifth term a₅ is 35. SeriesThe sum of the terms in a sequence.For the sequence 10, 20, 30, 40, the corresponding series is 10 + 20 + 30 + 40. Sum of an Arithmetic Series (Sₙ)T...

The Nth Term Formula aₙ = a₁ + (n - 1)d Use this formula to find the value of any specific term (aₙ) in an arithmetic sequence when you know the first term (a₁), the number of the term you want to find (n), and the common difference (d). The Sum of an Arithmetic Series Formula Sₙ = n/2 * (a₁ + aₙ) Use this formula to find the sum (Sₙ) of the first 'n' terms of an arithmetic sequence. It requires the number of terms (n), the first term (a₁), and the last term (aₙ).