Welcome to Mathnasium’s Math Tricks series. Today we are sharing a trick to find a quarter of any number.
The word quarter means “four parts the same,” or “four equal parts.” To find a quarter of a number, we first cut the number in half and then cut it in half again, which means we find the half-of-a-half. Once we find one fourth of the whole, we can verify that the answer plus itself, doubled, is the original number.
Follow the example below to find the quarter amount.
Example: You are sharing a 15-pack of gum with three friends and yourself. How many pieces of gum do you get?
Step 1: Determine the problem to be solved.
Since you are sharing fifteen pieces of gum with four people, you will get a quarter of the whole amount.
Step 2: Find a half of the original amount.
Half of 15 is 7 ½.
Step 3: Find the half-of-the-half.
Half of 7 ½ is equal to half of 7 plus half of ½.
Half of 7 is equal to 3 ½.
Half of ½ is equal to ¼.
So, a quarter of 15 is equal to 3 ½ + ¼ = 3 ¾.
Step 4: Check the answer.
The answer plus itself is equal to 3 ¾ + 3 ¾ = 7 ½.
The result doubled is equal to 7 ½ x 2 = 15.
Answer: You, and each of your friends, will get 3 ¾ pieces of gum.
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