Mental Maths Tricks: Solve Questions in Seconds
With only 15โ30 seconds per question on QuizOxa, mental arithmetic speed is critical. These tricks will help you calculate faster and think more clearly under pressure.
Why Mental Maths Matters in Quizzes
Mathematical quiz questions don't require advanced calculus โ but they do require fast, accurate mental calculations. Most maths questions in general knowledge quizzes test number sense, patterns, and key mathematical facts rather than complex problem solving.
Essential Numbers Every Quiz Player Should Know
5 Powerful Mental Maths Shortcuts
๐ก Multiplying by 11
For any two-digit number, add the two digits together and place the result in the middle. For example: 72 ร 11 โ 7_(7+2)_2 = 792. If the sum exceeds 9, carry over: 87 ร 11 โ 8_(8+7)_7 โ 8+1_5_7 = 957.
๐ก Squaring numbers ending in 5
Take the tens digit, multiply it by itself plus one, then append 25. For example: 35ยฒ โ 3ร4=12, then append 25 = 1,225. And 75ยฒ โ 7ร8=56, append 25 = 5,625.
๐ก Percentage shortcut
To find X% of Y, switch them around โ it's the same result. 8% of 50 = 50% of 8 = 4. This makes difficult-looking percentages trivially easy when one number is a simple fraction of 100.
๐ก Multiplying by 9
Use the finger trick: hold out 10 fingers. To multiply 9 ร 7, fold down your 7th finger. You have 6 fingers to the left and 3 to the right = 63. Works for 9ร1 through 9ร10.
๐ก Quick division by 5
Dividing by 5 is the same as multiplying by 2 and then dividing by 10. For example: 340 รท 5 โ 340 ร 2 = 680 โ 680 รท 10 = 68.
Common Maths Quiz Topics
- Prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29... (2 is the only even prime)
- Fibonacci sequence: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34... (each number = sum of previous two)
- Powers of 2: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024...
- Roman numerals: I=1, V=5, X=10, L=50, C=100, D=500, M=1000
- Geometric shapes: Know the formulas for area of circle (ฯrยฒ), triangle (ยฝbh), and rectangle (lw).