Learning About Two Things Together

This is a math book.
It has a math chapter.
The chapter is about numbers.

We look at two things at once.
We call this bivariate data.
That means two sets of numbers together.

Dot Pictures

We make dot pictures.
We call them scatter plots.
Each dot shows two numbers.

We look at the dots.
Do they make a pattern?
Some dots go up together.
Some dots go down together.
Some dots make no pattern at all.

Sometimes dots bunch together.
We call that a cluster.
Sometimes one dot is far away.
We call that an outlier.

Drawing a Line

Some dot pictures make a line shape.
We can draw a line through the dots.
We call this a line of best fit.

The line helps us guess new numbers.
We can use the line to make a prediction.

One story is about oil changes and car repairs.
We look at how many oil changes a car got.
We look at how much the repairs cost.
We draw dots for this.
Then we draw a line.
We use the line to guess the cost for 8 oil changes.

Tables for Groups

Some data is not numbers.
It is groups, like yes and no.
We call this categorical data.

We put this data in a table.
It has rows and columns.
We call it a two-way table.

One story is about tomatoes and gardens.
Emina likes tomatoes.
She grows them in her garden.
Her friend Renzo does not like tomatoes.
He does not grow a garden.

We ask many people the same questions.
Do you like tomatoes?
Do you have a garden?
We put the answers in a table.
Then we look for a pattern.

Thinking and Talking About Math

We look at pictures, like a graph of a basketball game.
It shows shots tried and shots made.
We look for a pattern in the dots.
We talk about what we see.
We explain our thinking to others.

A Fun Activity: Tongue Twisters

We say tongue twisters.
First, one person says it alone.
Then two people say it together.
Then more people join in.
We time how long it takes.
We write down the time each round.

Here are some tongue twisters:
"Work will win when wishy-washy wishing won't."
"Three witches wished three wishes, but which witch wished which wish."
"Peter Piper picked a peck of pickled peppers."