You need to know the least common denominator (LCD) of 4 and 40 if you want to add or subtract two fractions with 4 and 40 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 4 and 40 is 40.
Here is a math problem example where you need to know the LCD of 4 and 40 to solve:
3/4 + 2/40 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
40/4 = 10
40/40 = 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:
30/40 + 2/40 = 32/40
= 3/4 + 2/40 = 32/40
It's that easy! Once again, the lowest common denominator (LCD) of 4 and 40 is as follows:
40
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