Subtracting Mixed Numbers : āĻŽāĻŋāĻļā§ā§° āĻ­āĻ—ā§āύāĻžāĻ‚āĻļā§° āĻŦāĻŋāϝāĻŧā§‹āĻ—


Rule 1 (āύāĻŋāϝāĻŧāĻŽ ā§§): 



  • If the denominators are the same, subtract the numerators and keep the denominator same. (āϝāĻĻāĻŋ āĻšā§° āĻāϕ⧇ āĻšāϝāĻŧ, āϤ⧇āĻ¨ā§āϤ⧇ āϞāĻŦ āĻŦāĻŋāϝāĻŧā§‹āĻ— āϕ⧰āĻŋ āĻšā§° āĻāϕ⧇ ā§°āĻžāĻ–āĻŋāĻŦ āϞāĻžāϗ⧇āĨ¤)

  • Then subtract the whole numbers. (āϤāĻžā§° āĻĒāĻŋāĻ›āϤ āĻĒā§‚ā§°ā§āĻŖ āϏāĻ‚āĻ–ā§āϝāĻžāĻŦā§‹ā§° āĻŦāĻŋāϝāĻŧā§‹āĻ— āϕ⧰āĻŋāĻŦ āϞāĻžāϗ⧇āĨ¤)

  • Reduce or change to a mixed number if necessary. (āĻĒā§ā§°āϝāĻŧā§‹āϜāύ āĻš’āϞ⧇ āϏ⧰āϞ āĻŦāĻž āĻŽāĻŋāĻļā§ā§° āĻ­āĻ—ā§āύāĻžāĻ‚āĻļāϞ⧈ ā§°ā§‚āĻĒāĻžāĻ¨ā§āϤ⧰ āϕ⧰āĻŋāĻŦ āϞāĻžāϗ⧇āĨ¤)


Example | āωāĻĻāĻžāĻšā§°āĻŖ : 4 2/4 − 2 2/4 = 2 


Rule  2 (āύāĻŋāϝāĻŧāĻŽ ⧍): 



  • If the denominators are different, find the LCD first. (āϝāĻĻāĻŋ āĻšā§° āĻŦ⧇āϞ⧇āĻ— āĻšāϝāĻŧ, āĻĒā§ā§°āĻĨāĻŽā§‡ LCD āĻŦāĻŋāϚāĻžā§°āĻŋāĻŦ āϞāĻžāϗ⧇āĨ¤)

  • Change the fractions into equivalent fractions with same denominator.(āĻ­āĻ—ā§āύāĻžāĻ‚āĻļāĻŦā§‹ā§°āĻ• āĻāϕ⧇ āĻšā§°āϝ⧁āĻ•ā§āϤ āϏāĻŽāĻžāύ āĻ­āĻ—ā§āύāĻžāĻ‚āĻļāϞ⧈ ā§°ā§‚āĻĒāĻžāĻ¨ā§āϤ⧰ āϕ⧰āĻ•āĨ¤)

  • Then subtract the numerators and keep the denominator same. (āϤāĻžā§° āĻĒāĻŋāĻ›āϤ āϞāĻŦ āĻŦāĻŋāϝāĻŧā§‹āĻ— āϕ⧰āĻŋ āĻšā§° āĻāϕ⧇ ā§°āĻžāĻ–āĻ•āĨ¤)


Example | āωāĻĻāĻžāĻšā§°āĻŖ : 5 3/5 - 2 1/10 


1st: Find LCD


• LCD of 5 and 10 is 10. (ā§Ģ āφ⧰⧁ ā§§ā§Ļ ā§° LCD āĻšā§ˆāϛ⧇ ā§§ā§ĻāĨ¤)


2nd: Change fractions (āĻ­āĻ—ā§āύāĻžāĻ‚āĻļ ā§°ā§‚āĻĒāĻžāĻ¨ā§āϤ⧰ āϕ⧰āĻ•) : 3/5 = 6/10


3rd: Subtract (āĻŦāĻŋāϝāĻŧā§‹āĻ— āϕ⧰āĻ•) : 5 6/10 - 2 1/10 = 3 5/10


4th: Reduce (āϏ⧰āϞ āϕ⧰āĻ•) : 3 5/10 = 3 1/2 


Soln



3/5 = 6/10


5 6/10 − 2 1/10


3 5/10


3 1/2


LCD : Lowest Common Denominator (āĻ¸ā§°ā§āĻŦāύāĻŋāĻŽā§āύ āϏāĻžāϧāĻžā§°āĻŖ āĻšā§°))



  • LCD means the smallest common multiple of two or more denominators. (LCD āĻŽāĻžāύ⧇ āĻĻ⧁āϟāĻž āĻŦāĻž āϤāĻžāϤ⧋āϧāĻŋāĻ• āĻšā§°ā§° āφāϟāĻžāχāϤāĻ•ā§ˆ āϏ⧰⧁ āϏāĻžāϧāĻžā§°āĻŖ āϗ⧁āĻŖāĻŋāϤāĻ•āĨ¤)

  • LCD is used when adding or subtracting fractions with different denominators. (āĻŦ⧇āϞ⧇āĻ— āĻšā§° āĻĨāĻ•āĻž āĻ­āĻ—ā§āύāĻžāĻ‚āĻļ āϝ⧋āĻ— āĻŦāĻž āĻŦāĻŋāϝāĻŧā§‹āĻ— āϕ⧰āĻžā§° āϏāĻŽāϝāĻŧāϤ LCD āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āϕ⧰āĻž āĻšāϝāĻŧāĨ¤)


Rule 3 (āύāĻŋāϝāĻŧāĻŽ ā§Š)



  • If subtracting a mixed number from a whole number, rename the whole number as a mixed number. (āϝāĻĻāĻŋ āĻĒā§‚ā§°ā§āĻŖ āϏāĻ‚āĻ–ā§āϝāĻžā§° āĻĒā§°āĻž āĻŽāĻŋāĻļā§ā§° āĻ­āĻ—ā§āύāĻžāĻ‚āĻļ āĻŦāĻŋāϝāĻŧā§‹āĻ— āϕ⧰āĻž āĻšāϝāĻŧ, āϤ⧇āĻ¨ā§āϤ⧇ āĻĒā§‚ā§°ā§āĻŖ āϏāĻ‚āĻ–ā§āϝāĻžāĻ• āĻŽāĻŋāĻļā§ā§° āĻ­āĻ—ā§āύāĻžāĻ‚āĻļ ā§°ā§‚āĻĒ⧇ āϞāĻŋāĻ–āĻŋāĻŦ āϞāĻžāϗ⧇āĨ¤)

  • Regroup so the denominators become same. (regroup āϕ⧰āĻŋ āĻšā§° āĻāϕ⧇ āϕ⧰āĻŋāĻŦ āϞāĻžāϗ⧇āĨ¤)


Example | āωāĻĻāĻžāĻšā§°āĻŖ


9 − 6 2/8


1st: Rename 9 (⧝ āĻ• āĻĒ⧁āύ⧰ āϞāĻŋāĻ–āĻ•) : 9 = 8 8/8


2nd: Subtract (āĻŦāĻŋāϝāĻŧā§‹āĻ— āϕ⧰āĻ•) : 8 8/8 − 6 2/8 = 2 6/8 


​3rd: Reduce (āϏ⧰āϞ āϕ⧰āĻ•) : 2 6/8 = 2 3/4 


Ans (āωāĻ¤ā§āϤ⧰ ) = 2 3/4