Decimal Models and Place Value
VocabularyA decimal is what we use to show the fractional part of a whole.
The first place to the right of the decimal point is called the tenths place. If you take a whole and divide it into ten parts, a tenth is one of those parts. The second place to the right of the decimal point is called the hundredths place. If you take a whole and divide it into 100 parts, a hundredth is one of those parts. NotesA decimal is just another way to show the fractional part of a whole. When given a model, you can first determine the fraction shown and then turn it into a decimal. You can check what you've written as your decimal by using the "Dripping Paint" method on the decimal portion of your number. The decimal drops down to become a 1 and the digits to the right change to a 0. The resulting number should match the denominator in your fraction.
As with whole numbers, numbers with decimals can be written out in many forms.
Standard Form is the regular way you write a number. For example: 2,538.69 Written Form is when you write a number out using words. For example: two thousand, five hundred thirty-eight and sixty-nine hundredths Expanded Form is how you show the value of each digit in a number. For example: 2,000 + 500 + 30 + 8 + .6 + .09 Expanded Form can be written out of order. For example: .6 + 500 + 8 + .09 + 2,000 + 30 Expanded Notation is written as (2 x 1,000) + (5 x 100) + (3 x 10) + (8 x 1) + (6 x .1) + (9 x .01) Words and Numerals are also sometimes used. For example: 2 thousands, 5 hundreds, 3 tens, 8 ones, 6 tenths, 9 hundredths Words and Numerals can also be written out of order. STAAR Released Sample Question
|