At the end of the lesson, the students should be able to:
Know the number of digits in a given number.
Know the value of the digits in a given number.
Know the place value of digits in a given number.
Know the difference between the value and place value of a given digit in a given number.
When we say whole numbers, we mean numbers that do not have fractions or decimals attached to them.
Example
69 is a whole number.
42.05is not a whole number because it has 0.05 as part of the number.
3 ½ is not a whole number because of the ½ attached to it.
The development and use of numbers dates from ancient times and it is still being investigated and expanded by mathematicians today.
NUMBER OF DIGITS IN A GIVEN NUMBER (Revision)
In this lesson we will learn how to know the number of digits a particular number should have.
A given number should have the following number of digits;
NOTE; The digits in a number are written in groups of three from right to left.
Example
Write the number of digits in the numeral;
1)Ten million four hundred and fifty-five thousand two hundred and eighty –seven.
2)Six million one hundred and seventy-eight thousand six hundred and eleven.
3)Two hundred million nine hundred and fifty two thousand eight hundred and ten.
Solution
1)Ten million four hundred and fifty-five thousand two hundred and eighty –seven should have 8 digits. It is written as 10,455,287.
2)Six million one hundred and seventy-eight thousand six hundred and eleven should have 7 digits. It is written as 6,178,611.
3) Two hundred million nine hundred and fifty two thousand eight hundred and ten has 9 digit and it is written as 200,952,810.
Place Value
Place value in mathematics simply means that the place or position of a digit in a number determines its value. If the position or place of the digit changes, its value also changes.
Example 1
Find the place value and the value of the following whole numbers:
i) a) 3,696,312
b) 41,300,960
ii) Write the numbers in words.
Solution
i) a)3,696,312
ii) It can be written in words as
Three million, six hundred and ninety six thousand three hundred and twelve.
b) 41,300,960
This number is written in words as forty one million, three hundred thousand nine hundredand sixty.
The place value of 4 is ten million. The value of the 4 is 40 millionor40,000,000.
The place value of 1 ismillion. The value of 1is1 millionor1,000,000.
The place value of 3 is hundredthousand. The value of the 3 is 300,000or3 hundred thousand.
The place value of the two 0’s is ten thousand and thousand. However, the value of 0 is zero.
The place value of the 9 is hundred. The value of the 9 is900or9 hundred.
The place value of the 6 isten. The value of the 6 is 60or 6 tens.
The place value of the 0 is unitsor ones. The value of the 0 is zero.