You need to know the least common denominator (LCD) of 7 and 70 if you want to add or subtract two fractions with 7 and 70 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 7 and 70 is 70.
Here is a math problem example where you need to know the LCD of 7 and 70 to solve:
3/7 + 2/70 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
70/7 = 10
70/70 = 1
Step 2) Multiply each nominator with the respective answers from Step 1:
3 x 10 = 30
2 x 1 = 2
Step 3) Put it all together to solve the problem:
30/70 + 2/70 = 32/70
= 3/7 + 2/70 = 32/70
It's that easy! Once again, the lowest common denominator (LCD) of 7 and 70 is as follows:
70
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