It depends on what you are trying to calculate but the most common way I go to find percentage is to multiply by the number in decimal for ie. 50% = .5.
If you are looking for a way to do it quickly in your head I always take find out what 10% is like in the case of 100 it would be 10 so if I want to find 15% I know I can find 10% and if I cut what 10% is in half I will find 5% so likewise if I add what 10%+5% I will end up with 15%. For example, 10% of 100 is 10 half of 10 is 5 and 10+5 equals 15. If you need to find something like 20% or 30% I know that I can find 10% and instead of dividing(cutting it in half) I can multiply by 2 or 3. 10% + 10% =20%
I hope it helps, if you have more questions let me know!
You take the height times the width
Answer:
15
Step-by-step explanation:
Follow pemdas and multiply 6 and 2, then divide 9 and 3, finally, add the two together to get 15
6×2+9÷3
12+9÷3
12+3
=15
Answer:
The number is 7.
Step-by-step explanation:
The unknown number: x
9 (x + 7) = 126
Using the distributive property, 9x + 63 = 126
9x = 63
x = 7
Answer:
3x-2y=17........(1)
x=4y-1
substituting value of x in equation 1
3(4y-1)-2y=17
12y-3-2y=17
10y=17+3
y=20/10=2
again
substituting value of y in equation 1
3x-2×2=17
3x=17+4
x=21/3=7
:.x=7,y=2