BellringerThursday september 6, 2012

35 people go to a party and shake everyone’s hand

exactly once. Estimate how

many handshakes there will be!

Group Work

We will be working in groups ALOT this semester.

Knowing how to work well with others is an important part of life (Cheesy I know, but true!)

Expectations for Group Work:

RESPECT others

Ask for help when necessary

Help others when asked

STAY ON TASK :)

groups

Please move your desks in groups of 4!

inductive reasoning

Scientists and mathematicians look for patterns and try to draw conclusions from them!

A conjecture is an unproven statement that is based on a pattern or observation.

Looking for patterns and making conjectures is part of a process called inductive reasoning.

Handshake activity

35 people go to a party and shake everyone’s hand

exactly once. How many handshakes

are there?

handshake activity

In groups of 4, answer questions 2-5 on your worksheet. I will be walking around answering questions as needed!

If you’re stuck, actually shake hands with the people in your group and count how many total handshakes there are.

Let’s do part of number 2 together.

handshake activity

You will have 30 minutes to

complete this activity.

If you finish early, raise your hands and let me know!

QuickTime™ and aH.264 decompressor

are needed to see this picture.

number 2

# of people

1 2 3 4 5

# of total handshak

es0 1 3 6 10

Does anyone Does anyone see any see any

patterns?patterns?

number 3Try it this

way!

# of people

1 2 3 4 5 6 35

# of handshake

s per person

# of total handshake

s

0 1 3 5 34

0 1

1

2 4

3 6

5

10 15 595

number 4

How many handshakes would there be at a party of 40 people?

Let’s generalize...

# of handshakes=

6 volunteers???

number 4

How many handshakes would there be at a party of 40 people?

# of handshakes=

# of handshakes= =

780 handshakes

Number 5If there were 253 handshakes at the

party, how many people were there?

23 people

homework

Get Geometry Binder/Binder Tabs by Friday!