1. Decimals & Fractions: Parts of a Whole
Understanding Numbers
Key Learnings:
Always ask yourself, “What’s the whole?”
The decimal point in numbers separates whole numbers from parts/fractions of a whole number.
Decimal numbers/fractions exist between whole numbers on a number line.

2. What’s the whole??
In order to understand what a fraction or decimal means, you must understand what the whole is that you are talking about.
If this is the whole...
what fraction of the whole is represented here?

3. What’s the whole?? If this is the whole, a string of 10 beads...
what fraction of the whole is green?

4. What is the whole?? If this is the whole...
what fraction of the whole is black?

5. What’s the whole??
A whole is represented as ‘1’ or “one” in our place value system.
Ten wholes is ’10’ or a “ten”; one hundred wholes is ‘100’ or a “hundred”, and so on.
These wholes are on the left side of the decimal point.

6. Fraction-
numbers used to name part of a whole or part of a set
Decimal-
a way to describe fractions using place value; a decimal point separates the wholes from the parts

7. Examples:
This is the whole. It is represented as 1/1 as a fraction. It is represented as 1 or 1.0 or “one” as a decimal.
What part of the whole is represented here? The whole is divided into 10 equal pieces. Therefore, 1/10 is the fraction and 0.1 or “one tenth” is represented here.

8. Examples continued...
This is the whole. It is represented as 1/1 as a fraction. It is represented as 1 or 1.0 or “one” as a decimal.
What part of the whole is represented here? The whole is divided into 100 equal pieces. Therefore, 15/100 is the fraction and 0.15 or “fifteen hundredths” is represented here.

9. A Twist...
Now this is the whole. It is still represented as 1, 1.0, or “one”.
So how much is represented by the light blue bar?