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 diagram shown above, the whole number is 5,638,742. The lowest place value of the whole numbers is the units. Hence, from right to left (on the left hand side of the decimal point) we have: units, tens, hundreds, thousands, ten thousands, hundred thousand millions.
The fraction part of the decimal number lies on the right hand side of the decimal point. The highest place value of the fraction part or decimal is the tenth and it reduces towards the far right as follows: tenth, hundredth, thousandth, ten thousandth etc. as shown in the illustration above.
What is the place value and value of the underlined digits in the decimal numbers below?
(a) 14.204 (b) 849.916 (c) 1476.8
(d) 0.1436 (e) 532.7539 (f) 48.231
What is the total value of the underlined digits?
(a) 53.2 (b) 64.85 (c) 6893.2638
=5 tens and 2 tenths
=50 + 0.2
=4 units and 5 hundredths
=4 + 0.05
= 6 thousands and 9 tens
=6000 + 90
The knowledge of decimal place value and value can be applied when illustrating decimals on an Abacus or Notation Board.
NB: The decimal point always comes between the units and tenths.
The Notation Board is similar to the Abacus.
Unit 10 Lesson 3: Exercise 1
Write the place value and value of the underlined digits.
Unit 10 Lesson 3: Exercise 2
Find the total value of the underlined digits in each of the decimals below.
Unit 10 Lesson 3: Exercise 3
Write the decimals illustrated on these notation boards.
Make abacus pictures to illustrate these decimal numbers.