I know you hae to move the decimal point when you multiply and divide decimals but why do you have to do so?
2007-08-28 03:34:39 · 5 answers · asked by cdgasmartie2005 1 in Science & Mathematics ➔ Mathematics
Consider the example 5.3456 x 1000. As you said we have to move the decimal point, the answer will be 5345.6. The thing behind is 5.3456 can be written as 53456/10000.Now
53456/10000 x 1000. Here 4 zeros from the numerator and denominator get cancelled and one zero is left in the denominator. So 53456/10 becomes 5345.6. Similarly with division.
2007-08-28 03:45:28 · answer #1 · answered by Anonymous · 0⤊ 0⤋
A decimal represents a number between 0 and 1. It is a fraction, or a part of 1. Moving the decimal allows for the expression of the correct answer. For instance, 1/2 is represented by the decimal .5. If i Multiply .5 by 2 I will get the answer 1. 0, or 1. If I divide 1.0 by 2, I will get.5 because I cannot divide the number one by two without the place saving zero after the decimal point.
2007-08-28 03:47:34 · answer #2 · answered by fangtaiyang 7 · 0⤊ 0⤋
Because they represent fractions and the decimal point is what makes a fraction get larger are smaller when written in decimal form.
2007-08-28 03:39:10 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Example 1
When 2 is multipled by 6.4 the figures in the answer are 128.
However it is obvious that 2 x 6.4 is NOT 128.
It MUST be 12.8 by applying common sense.
Therefore 2 x 6.4 = 12.8
Example 2
48.3 / 3 gives figures of 161
Again common sense says answer must be 16.1
Conclusion
Estimate roughly what answer is and insert decimal point accordingly.
2007-08-28 04:26:49 · answer #4 · answered by Como 7 · 3⤊ 0⤋
so it can be right
2007-08-28 03:38:52 · answer #5 · answered by Navita 3 · 0⤊ 0⤋