Verdict. The Microsoft Lumia 638 is an attractive budget friendly smartphone with the latest Windows OS and support for 4G LTE Cat4. It features a powerful Qualcomm Snapdragon processor but the lack of front camera is a big disappointment.
Steps. 1. Make sure that the denominators of every fraction that you're going to add or subtract are the same. 1  If the numbers are different, you can't add or subtract the fractions as-is.2  You can, however, perform the operations necessary to create fractions with like denominators, in which case you can add and subtract them.teps. 1. Make sure that the denominators of every fraction that you're going to add or subtract are the same. 1  If the numbers are different, you can't add or subtract the fractions as-is.
6. Multiply the numerators and denominators of the fractions. Therefore, the next step is to multiply the numerators and denominators of the fraction to get the new numerator and denominator of the final answer. 1  To multiply the numerators, just multiply 2 x 1 to get 2.. Write the reciprocal of the whole number. To find the reciprocal of a number, simply switch the numerator and the denominator of the number. Therefore, to find the reciprocal of 4/1, simply switch the numerator and denominator so that the number becomes 1/4.