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Easy Method of Multiplication Last year I saw 4 junior high school teens who can’t multiply two digit number like 25 times 25. I was not surprised with this because many children use calculators and computers to do their math. To make them interested in math, I teach them simple “tricks” or shortcut when multiplying two digit numbers that ends in 5. These two number should be the same. Example: 25 x 25, 35 x 35, 45 x 45, 55 x 55. I demonstrate this onto the white table paper on top of the examining table. 25 x 25 = 625 To get 625 the easy way,I instruct them to write 25 on the right side because 5 x 5 = 25. To get the number on the left of 25, add 1 to 2 = 3, then multiply 3 x 2 = 6, then write 6 on the left of 25 you get the answer of 625. Do this with 35 x 35. Write 25 on the right and add 1 to 3 = 4, 4 times 3 equals 12. Write 12 to the left of 25 and it is 1225. 45 x 45 = 2025, 55 x 55 = 3025 65 x 65 = 4225 Most of the teenagers who learned this method were excited with it and some of them said they will mention it to their math teacher. One child even commented, “I will tell our principal about this.” Leo Leonidas MD, FAAP
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