Sally thinks of a number, multiplies it by 2, adds 2, divides by 2 and then subtracts 2. Her answer is 2. What was her original number?
Math Game
Arithmetic
Missing Number
But try the problem first...
Answer: 3
Australian Mathematics Competition Upper Primary
2014 UP 15
Secrets of Mental Math - Arthur T. Benjamin
First Hint
This sum is a tricky one. You can play game with this sum too
First we can start with a diagram where the number by which we are starting is X (assume).
Final Hint
In Hint 1 its clear that how to solve this problem.Try this ....
But if you really want a final hint then we have to solve it in reverse.Lets See another picture.
So the answer is 3.
AMC - AIME Boot Camp... for brilliant students.
Use our exclusive one-on-one plus group class system to prepare for Math Olympiad
Sally thinks of a number, multiplies it by 2, adds 2, divides by 2 and then subtracts 2. Her answer is 2. What was her original number?
Math Game
Arithmetic
Missing Number
But try the problem first...
Answer: 3
Australian Mathematics Competition Upper Primary
2014 UP 15
Secrets of Mental Math - Arthur T. Benjamin
First Hint
This sum is a tricky one. You can play game with this sum too
First we can start with a diagram where the number by which we are starting is X (assume).
Final Hint
In Hint 1 its clear that how to solve this problem.Try this ....
But if you really want a final hint then we have to solve it in reverse.Lets See another picture.
So the answer is 3.
AMC - AIME Boot Camp... for brilliant students.
Use our exclusive one-on-one plus group class system to prepare for Math Olympiad
