The knowledge of the method of Multiplying whole numbers with vertical presentation is a prerequisite here. Once you master Multiplying whole numbers, the methods described here, are easy to follow.
But remember that, simple things need perfection and perfection is not a simple thing.
Study the Examples and solve the problems given in exercise and check with the Answers.
Multiplying Decimals by 10, 100, 1000 etc.
When a decimal number is multiplied by 10, the decimal point moves to the right by one place.
When a decimal number is multiplied by 100, the decimal point moves to the right by two places.
When a decimal number is multiplied by 1000, the decimal point moves to the right by three places.
and so on.
Thus, we observe :
When a decimal number is multiplied by numbers like 10, 100, 1000...., the decimal point in the given decimal number moves as many places to the right as the number of zeros in the multiplier. If there are not enough (adequate) places on the right side, we keep '0' s in those places.
9.62 x 10 = 96.2 ( decimal point shifted 1 place to the right )
1.13 x 10000 = 11300 ( decimal point shifted 4 places to the right )
6.9732 x 1000 = 6973.2 ( decimal point shifted 3 places to the right )
0.01 x 100 = 1 ( decimal point shifted 2 places to the right )
0.999 x 100000 = 99900 ( decimal point shifted 5 places to the right )
and study the explanation given to Example 19, there.
Now,decimal point will be placed 5 places (as in the multiplying decimals 2 + 3 = 5) from right.
∴ 14.32 x 2.513 = 35.98616 Ans.
Find the products
39.641 x 100
34.754 x 100000
15.05 x 1000
0.08 x 10
0.7 x 10000
63.47 x 8
2.375 x 148
0.235 x 0.137
0.075 x 0.009
For Answers, see at the bottom of the page.
Progressive Learning of Math : Multiplying Decimals
Recently, I have found a series of math curricula (Both Hard Copy and Digital Copy) developed by a Lady Teacher who taught everyone from Pre-K students to doctoral students and who is a Ph.D. in Mathematics Education.
This series is very different and advantageous over many of the traditional books available. These give students tools that other books do not. Other books just give practice. These teach students “tricks” and new ways to think.
These build a student’s new knowledge of concepts from their existing knowledge. These provide many pages of practice that gradually increases in difficulty and provide constant review.
These also provide teachers and parents with lessons on how to work with the child on the concepts.
The series is low to reasonably priced and include