Decimal introduction and place value

 In this lesson, we're doing a new topic. The new topic is decimal. Previously we learned about the fraction, now we're going to change the fractions into decimals and decimals into fraction, then we're going to learn about place value in decimal.

 Firstly, changing decimal into fraction. Changing decimal into fraction is like this. Decimals are different from the the fraction but they're special fraction which the denominators are 10, 100, 1000, etc.

So for example, 1 and 59/100 is 1.59.

  Secondly I want to talk about is place value in decimal.
Decimal place value is similar as the whole number place value.
The only difference is there is a tenth, hundredth, thousandth, etc.
Tenth is 1/10 in fraction, hundredth is 1/100 in fraction and in goes on 1000, 10000, 100000 etc.

  For example 345.123.
We all know now that 3 is 300, 4 is 40, 5 just 5, and now,
1 is 1/10 because 1 is in tenth place, 
2 is 1/100 because 2 is in hundredth place, 
and 3 is 1/3000 because 3 is in thousandth place.

Second example is "write  34.56 in expanded form."
Expanded form is another way to show how much number are in each digits
that represents.

Therefore (3 x 10) + ( 4 x 1) + (5 x 1/10) + (6 x 1/100).


Third and last example is "What is the place value of 5 in 123.475?"
The answer is thousandth. Reason is 5 in the thousandth place,
the place value of 5 is 5 x 1/1000 = 5/1000.