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Warm Up: Find the following sums. 1. . 2. . 3. . 4. . Sequences. Sometimes it is relatively easy to find the pattern of a sequence. and sometimes it is a little more difficult. Finding Successive Differences. 74. 14 22 32 44 58 ___. 8 10 12 14 .
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Warm Up: Find the following sums 1. 2. 3. 4.
Sequences Sometimes it is relatively easy to find the pattern of a sequence and sometimes it is a little more difficult
Finding Successive Differences 74 14 22 32 44 58 ___ 8 10 12 14 16 2 2 2 2
Finding Successive Differences 202 2 6 22 56 144 ___ 4 16 34 58 88 30 12 18 24 6 6 6
Find the next term in the sequence 235 5 15 37 77 141 ___ 10 22 40 64 94 30 12 18 24 6 6 6
Sums of Numbers Recall that we were able to quickly find the sum of consecutive integers by using the Gauss method 1+2+3+…+99+100 = 5050 (100 ÷ 2)(101) =
Sums of Numbers Write a formula for finding the sum of the first n counting numbers 1+2+3+…+(n-2)+(n-1)+n= (n ÷ 2)(n+1) =
Sums of Numbers Here is an interesting way to come up with this formula Let S=1+ 2 + 3 +…+(n-1)+n + S=n+(n-1)+(n-2)+…+ 2 +1 2S=(n+1)+(n+1)+(n+1)+…+(n+1) 2S=n(n+1)
Sums of Odd Counting Numbers See if you can find the sum of odd consecutive counting numbers. Find the sum of the first n odd counting numbers S=1+3+5+7+…+(2n-1) Hint: Try taking a couple of sample sums
Sums of Odd Counting Numbers 1=1 1+3=4 1+3+5=9 1+3+5+7=25
Summary Sum of n consecutive numbers Sum of n consecutive odd numbers
Find the sum of the first n consecutive even numbers S=2+4+6+8+…+2n S=1+2+3+…+(n-2)+(n-1)+n 2S=2(1+2+3+…+(n-2)+(n-1)+n) 2S=2(1)+2(2)+2(3)+…+2(n) 2S=2+4+6+8+…+2n S=2S
Figurate Numbers Numbers and sequences of numbers that are formed based on the geometric arrangement of points
How many dots are in the next figure? 21 6 2 3 4 5 1 1 1 1
How many dots are in the 99th figure? Figure 1 2 3 4 5 … n # of Dots 1 3 6 10 15 … ?
The number of dots in the nth figure is the same as the sum of the first n counting numbers
Homework Sequence, Sums and Figurative Numbers Worksheet