Do you lose your keys, forget where you stashed your sunglasses and then make a crack about how your memory isn’t what it used to be? If so, you can take steps to boost your brainpower and feel better about occasional mental misfires.

One top way to stay mentally sharp is to exercise your brain, according to Harvard Medical School. In fact, mental exercise may “activate processes that help maintain individual brain cells and stimulate communication among them.”

Top ways to get a mental workout include:

- Acting as a mentor or teacher
- Learning a new skill
- Taking up a hobby
- Volunteering for a good cause

But there’s another way to get some mental exercise that’s easy, fun and can be done at home — solve our In the Balance brain teaser. This math and logic puzzle gives you three perfectly balanced scales with different shapes on each side. A fourth scale has shapes only on the left side. You need to study the three balanced scales to figure out how many shapes are needed to balance out the last one.

Tackling brain teasers like this can jog your brain and strengthen your synapses in a fun way. This brain teaser works the parts of the brain that handle math, numbers and spatial relationships. These parts of your brain are essential for everyday tasks like budgeting, doubling a recipe and comparison shopping at the grocery store.

Oh, and here’s one more easy and fast way to improve your memory: bite your tongue when you get the urge to make a quip about your aging brain. Research shows that negative stereotypes about aging and memory can actually be self-fulfilling. Middle-aged and older people do better on memory challenges after being exposed to positive messages about aging and preserving memory.

So go ahead, believe in your brainpower and take on this brain teaser with confidence.

How’d you do? Click here to check your work.

**Did you solve the puzzle correctly?** **Leave a comment to let us know how you did and what you thought of this puzzle.**

I got it right. Love to do number puzzles. Send more please.

Great to hear, Virginia! You can find additional puzzles here on our site.

Good grief, I used to think I was good at algebra, but that was 40 yrs ago. I can’t get the answer even with all the explanations given..I am out of touch.

Answered correctly. great teaser!

Got it right, 1 green triangle. FUN!

My answer to the brain teaser was correct.

Thanks for giving this rusty brain a workout..

We’re glad you liked it!

Very Fun!!!

We’re so glad you liked it!

By inspection I knew that I had to substitute a triangle for the circle in #2. So in # 1, I calculated that 2/3 triangle = 1 circle. Then in #2 we have 2/3 triangle =one square. In #3 we have 2/3 triangle X 3 =2 triangles balances 4 diamonds. Finally in #4 it takes one triangle to balance two diamonds.

I will be 89 in august and love to solve brain-teasers.

We’re glad you liked the brain teaser, John! Thank you for sharing!

I solved this puzzle in the amount of time it took me to look at all four of the scales, in other words, in less than a minute.

Two diamonds are equal to one and one half circles or one and one half squares, and it is plain to see that one triangle is the same as one and one half circles. So the answer is one triangle. Thanks.

I figured it out by giving each side of the scale a number value of a 100. Three squares and three circles equal 100, four diamonds equal 100, so two diamonds equal 50. Since two triangles equal three circles equal 100, and each diamond is worth 25 as four are a 100 and each triangle equals 50. It becomes a simple math problem. 50 + 25 + 25 = 100

Love Math and Logic.

Since 1 square = 1 circle, then 3 circles = 4 diamonds or 2 triangles

Thus 2 diamonds would = 1 triangle and scale 4 would be balanced.

The first scale shows one triangle is 1/2… From there it is easy to follow and deduct that each diamond is 1/4. It was easy. Thank you.

I had the correct answer! I like this type of puzzle, thanks for you tips and exercises!

You’re welcome, Ann!

Recently I have been experiencing some neurological issues. There was a time when I would have been able to solve this puzzle in 2 seconds. Today it took me about 30 seconds. I’ll share this with my neurologist at my next appointment.

The square and the circle are equal.

2 triangles = 3 circles, or 3 squares.

4 diamonds = 3 circles, or 3 squares

therefore 2 diamonds = 1.5 triangles

I have a headache

Too easy. Want more! To show my work:

Since 1sq=1dot, then 3 sqs= 3 dots and 2 triangles

2 triangles = 4 dimonds; therfore 2 dimonds = i am late for lunch.

I got the right answer. Thanks.

g= green triangle, b= blue circle, r= red square and p= purple quadrilateral

Scale 1. 2g= 3b

Scale 2. 1r= 1b

Scale 3. 3r= 4p If 2g = 3b and 1r=1b and 3r= 4p then 3b=4p so 2g=4p and 1g= 2p

Scale 4. one green triangle will balance with two purple quadrilaterals.

Too easy. Want more!

g= green triangle, b= blue circle, r= red square and p= purple quadrilateral

Scale 1. 2g= 3b

Scale 2. 1r= 1b

Scale 3. 3r= 4p If 2g = 3b and 1r=1b and 3r= 4p then 3b=4p so 2g=4p and 1g= 2p

At 82 I do not care for fractions.

Scale 2 : 1 red = 1 blue so 3 red = 3 blue

SCALE 1, 2 and 3: 2 green = 3 blue = 3 red = 4 purple

ERGO 1 green = 2 purple

Loved it. It didn’t take too long to figure out using math and logic. While I enjoy puzzles like this, I know others who would think it was too hard to figure out and not understand the logic in it. Send more!!

Took me about 5 – 10 minutes to solve in my head.

It was a little challenging at first, but after 2 minuets I made my decision, based on similar reasoning.

I used vison reason of deduction, rather than a math equation.

I solved it thinking much as your solution indicated. I wrote down 3 circles=2 triangles and 3 squares=2 triangles and since 3 squares=4 diamonds, then only 1 triangle would equal 2 diamonds or 1/2 the weight of the 4 diamonds.

Step One:

Before Beginning: (Using education techniques from back in the 50’s)

Establish the Standard of Value (Knows):

Move Scale Number 1 into Scale No. 2 Position–– This places Scale 2, In Scale No. 1’s Former Position.

The Standard (the known) is as follows: 1 Block (or) Square is equivalent to 1 Dot (or) Bullet:

The unknown objective (or) quantity required [to be determined] is a number of Triangles – thus: A Triangle equates to a whole number of 1

Step Two: [But for switching the scales around for clarity, is actually Step 1.]

Given: 2 Triangles = 3 Dots/Bullets Thus (by deduction): 2 ÷ 3 = 2/3rds

Thus: 2/3rds multiplied by 3 = 2 (Triangles with a value of 1)

Step Three: [Multiplying 3 Blocks/Squares with a value of each being 2/3rds, which equates to 2 divided by the number of Diamonds on the scale]

Given: [The number of 2 (the value of 3 blocks) ÷ 4 (Diamonds) = a number value of .5]

Thus: 4 Diamonds with each having a value of .5 = a combined value of 2 [.5 x 4]

Step Four: [Multiplying the Diamond value of .5 times the number of Diamonds on the Scale (2)]

Given: Each Diamond equates to a value of 0.5

Thus: 2 Diamonds at a value of 0.5 multiplied by 2 (the number of diamonds on the scale) equates to the number value of 1–––

Thus, only one Triangle is necessary to balance the scale.

1 triangle.

The official solution is correct but the logic is not appropriate.

It should start with the scale number 4.

The problem should be addressed by successive substitution.

We have 2 Diamonds there on the left hand side.

Scale 3 tells us that 4 Diamonds is equal to 3 Squares. So, 2 Diamonds will equal 3/2 Squares.

Scale 2 tells us that one Diamond is equal to 1 Circle. So, 2 Diamonds will equal 2 Circles.

Scale 1 tells us that 3 Circles is equal to 2 Triangles. So, 2 Diamonds will equal 1 Triangle.

(I have been an AARP member for over 30 years.)

Yes, I solved it correctly through logical thinking.

Allie this is great! My son-in-law is recovering from a brain injury. Out of concern about his memory he started taking a pill to improve his memory. This is a reminder you don’t need a pill, you just need to exercise your brain. It was easy when you read the directions and don’t complicate it with math. LOL.

We’re glad you liked it!

g= green triangle, r= red square, b= blue circle and p= purple quadrilateral

Scale 1: 2g=3r

Scale 2: 1r= 1b

Scale 3: 3r=4p. If 2g=3r and 3r=4p then 2g=4p so 1g=2p

Scale 4: 1 green circle = 2 purple quadrilaterals

Easy.

Got it! Worked backwards from 4 diamonds divided by 2 = 3 red squares divided by 2 =1 1/2 squares etc.

Awesome!

I got the right answer right away, but can’t honestly say I would have bet the house on it!

Very easy for me.

3 circles = 2 triangles; therefore 1 circle = 2/3 triangle

1 square = 1 circle

4 diamonds = 3 squares ; therefore, 1 diamond = 3/4 square

ergo:

2 diamonds = 6/4 squares

6/4 squares = 6/4 circles

6/4 circles * 2/3 triangles/circle = 12/12 triangles = 1 triangle

Got it! Good brain teaser.

We’re glad you liked it, Ann!

Same answer, calculated differently: 3R/s = 2G/t, 3R/s = 4P/d, 2P/d = 1G/t

good algebraic problem. Love it

Enjoy these Brain Teasers. Look forward to doing more.

Got it! Easy!

Solved but likely took longer than I would have at a younger age! (Age 88)