Okay, here we go.
With simpler decimals, this is a bit easier so I'll explain that first to make sure you get the basic idea.
Let's say you had a decimal for .75 and wanted to create the fraction mathematically. To do this you would:
First divide the decimal by 1 so .75/1
Then multiply be a multiple of 10 that eliminates the decimal so in this case 100
so you now have 75/100
When you simplify that fraction by dividing by 25, you of course get 3/4
Now on to your more complicated question:
Let's assign a variable to your repeating decimal so:
x=.1515151515
Now, let's identify the repeating digits, here they are .15
Move one set of the repeating digits in front of the decimal so now we get:
100x=15.1515151515
Now you have two equations, they are:
x=.1515151515
100x=15.1515151515
Combine the equations into one equation:
100x-x=15.1515151515-.1515151515
99x=15
15/99
simplify and you get 5/33
Surface area of a sphere = 4πr² = 4π(15)² = 900π m²
Surface area of a sphere = 4πr² = 4π(10)² = 400π m²
Answer:
B. 550
Step-by-step explanation:
550 is the smallest number that becomes 600 when rounded to the nearest hundred
Answer:
This is a complete lesson with instruction & exercises for 5th grade about multiplying decimals by decimals. The interpretation for multiplying a decimal by a decimal is to think of it as taking a fractional part of a decimal number (the symbol × translates to "of"). The lesson compares multiplication by a decimal to scaling & shrinking a stick. Lastly, it shows the common shortcut to decimal multiplication (multiply as if there were no decimal points; the answer has as many decimals as the factors have in total.)
In the video below, I explain the rule for multiplying decimals (put as many decimal digits in the answer as there are in the factors.) I explain where this rule comes from, using fraction multiplication. The lesson continues below the video.
(red pens + black pens) / total pens
(4 + 6) / 15 = 10/15 = 2/3
