Kungfu math p4 slide11 (decimals up to 3 decimal places)pdf
1. Decimals
Decimals up to 3 decimal places
What will we learn today?
• notation and place values (tenths,
hundredths, thousandths)
• conversion of a decimal to a fraction
3. Decimals
A Decimal Number
(based on the number 10)
contains a Decimal Point.
Examples:
230.01, 0.56, 1.20
4. Place Value
To understand decimal numbers, we must
first know about Place Value.
When we write numbers,
the position (or "place") of each number is
important.
5. Example
In the number 427:
the "7" is in the Units position, meaning just 7
(or 7 "1"s),
the "2" is in the Tens position meaning 2 tens
(or twenty),
and the “4" is in the Hundreds position,
meaning 4 hundreds.
6. In the number 427,
As we move to the left, each position is 10 times bigger!
427
From Units, to Tens, to Hundreds
7. In the number 427,
As we move to the right, each position is 10 times smaller.
427
From Hundreds, to Tens, to Units
8. If we pass the unit value,
we have to first write a decimal point
427.1
and this value is 10 times smaller than the units
9. Decimal Point
427.1
“four hundred twenty seven and one tenth"
But,
we usually just say
“four hundred twenty seven point one"
10. Decimal Point
The decimal point is the most important part of
a Decimal Number.
It is exactly to the right of the Units position.
Without it, we would be lost ... and not know
what each position meant.
11. With that, we can continue with smaller and
smaller values, from tenths, to hundredths, and
so on.
See the example below,
tenths
units hundredth
tens
27.198
decimal point
thousandth
12. A Decimal Fraction
is a fraction where the denominator (the bottom
number) is a number such as 10, 100, 1000, etc
13. A Decimal Fraction
is a fraction where the denominator (the bottom
number) is a number such as 10, 100, 1000, etc
For example,
24
2.4 = 10
14. A Decimal Fraction
is a fraction where the denominator (the bottom
number) is a number such as 10, 100, 1000, etc
For example,
124
12.4 = 10
15. A Decimal Number
can be a combination of
Whole Number and Decimal Fraction
4
12.4 = 12 and 10
