Place Value

We can use the smaller number as a benchmark to estimate the greater number

A place-value chart shows the value of the digit in a number

Value of a digit is found by multiplying it with its place value

The first digit from the right has a place value ones, second has tens, and so on

The digit in ones place has value = digit x 1. The digit in tens place has value = digit x 10 and so on

To write the word name and the short word name of a number, write the number in the place value chart

Then look for commas that separate groups of 3 digits. The commas help you identify the thousands, millions, billions, and so on

A number written in the usual place-value way is said to be in standard notation

To find the short word name, write the first group as numbers. Follow by the group value in words. For example, the short word name for the number 234,000 is 234 thousand

To write a number in expanded form, multiply each digit by its place value, and place addition signs between the digit values. For example, 5,665 in expanded form is 5,000 + 600 + 50 + 5