Maths Tricks with Numbers
Trick 1:Quick Square
- If you need to square a 2 digit number ending in 5, you can do so very easily with this trick.
- Mulitply the first digit by itself + 1, and put 25 on the end.
- That is all!
- Ex:25 ie(2*(2+1))&25
Answer:625
Trick 2: Multiply by 5
- Take any number, then divide it by 2
- If the result is whole, add a 0 at the end.
- If it is not, ignore the remainder and add a 5 at the end.
- 2682 x 5 = (2682 / 2) & 5 or 0
- 2682 / 2 = 1341 (whole number so add 0)
- Ans:13410
- Let’s try another:5887 x 5,2943.5 (fractional numbers (ignore remainder, add 5)
Answer: 29435
Trick 3: Tough Multiplication
- If you have a large number to multiply and one of the numbers is even, you can easily subdivide to get to the answer
- Ex:32 x 125, is the same as: 16 x 250 is the same as: 8 x 500 is the same as: 4 x 1000 = 4,000
Trick 4: Subtracting from 1,000
- To subtract a large number from 1,000 you can use this basic rule: subtract all but the last number from 9, then subtract the last number from 10:
- Ex:1000-648
- subtract 6 from 9 = 3
- subtract 4 from 9 = 5
- subtract 8 from 10 = 2
Answer: 352
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