# MATH

• ### WELCOME TO MATH!

Now that you are familiar with thousands, let's move on to ten thousands and hundred thousands!

Please read the first two paragraphs at the top of page 42.
Please look at the place-value chart in the middle of the page.
You are very familiar with the green portion of the chart which represents the
'hundreds,' 'tens,' and 'ones' place-value columns.

Now as you look at the full chart including the purple portion, you can see they have displayed the numbers mentioned in the two paragraphs we read (regarding how many people were at a summer Olympic event, and the total number of people at five events).

It is interesting to see the numbers also written in expanded form and standard form beneath the chart.

IT IS IMPORTANT TO NOTE that although a comma is not required when writing a 4-digit number (1000), A COMMA MUST BE USED WHEN WRITING A NUMBER WITH 5 OR MORE DIGITS.
The comma separates the digits in the thousands and hundreds places.

Look at the difference when trying to read the following numbers:  1000000
1,000,000

With the commas it is much easier to see that the number is 'one million.'
------------------------------------------