At the end of this lesson, students should know and understand the place value and value of decimal numbers.
The decimal point separates the whole number from the fraction part of a decimal number. In the above diagram, the whole number is 342,368. The
lowest place value of whole numbers is the units. Therefore, from right to left on the left hand side of the decimal point: units, tens, hundreds, thousands, ten thousands and hundred thousands.
On the right hand side of the decimal point, the highest place value of the fraction part begins: tenth, hundredth, thousandth, etc. as shown in the illustration above.
Write the value and place value of the underlined digits in the following decimal numbers.
a) 2486.08 b) 35276.826
c) 359,901.620 d) 24.241
e) 19.4211 f) 78 9.1515
What is the total value of the underlined figures in each of these?
a) 24.5 b) 828.84
a) 24.5 = 2 tens and 5 tenths
= 20 + 0.5
b) 828.84 = 2 tens and 8 units
= 20 + 8
An Abacus or Notation Board can be used to illustrate decimals based on the knowledge of place value. Let’s look at the Abacus below.
Notation boards work in the same way as the Abacus. Below are some illustrations on Notation boards.