CBSE Class 3 Mathematics Brain Teasers Worksheet

WORKSHEET - 2 (BRAIN TEASERS)

Q1. Guess the mystery number

1. It is less than 1000

2. Its tens digit is 2

3. Its hundreds digit is 4 more than tens digit

4. The sum of its digit is

Q2. Draw the chocolate bar so that one part has two more pieces than the other.

Q3. These squares have been cut out from a hundreds chart fill in the empty squares.

26 28

37

46 48

Q4. Use only six seeds of any pulse for the following activity

a) Six seeds have been placed here in such a way that rectangle has 3 seeds and the

triangle has 5

b) Now rearrange the 6 Rajma seeds in such a manner that there are 5 seeds in the

rectangle and in the triangle

24

17

Dow

Worksheet - 2 (Brain Teasers)

Question 1. Guess the mystery number
1. It is less than 1000
2. Its tens digit is 2
3. Its hundreds digit is 4 more than tens digit
4. The sum of its digit is
Answer:
The mystery number is 621.
We can solve this step-by-step using the clues:
- First, the tens digit is given as 2.
- Second, the hundreds digit is 4 more than the tens digit, so it is: \( 2 + 4 = 6 \).
- Third, the sum of all three digits in this puzzle is 9. Therefore, the ones digit is: \( 9 - 6 - 2 = 1 \).
- Putting these digits together in the place value chart gives: 621.

In simple words: First, look at the clues. The tens place has a 2. The hundreds place has 4 more, which is 6. All digits add up to 9, so the ones place must have 1. This gives us 621.

Exam Tip: Always start with the clues that give you a direct digit, like the tens digit, and build the other digits from there.

Question 2. Draw the chocolate bar so that one part has two more pieces than the other.
Answer:
To divide a chocolate bar so that one part has two more pieces than the other, we can use a bar with 6 total pieces:
- Divide the 6 pieces into two parts: one part has 4 pieces and the other part has 2 pieces.
- Here, 4 pieces is exactly 2 more than 2 pieces (\( 4 - 2 = 2 \)).

Here is the drawing of the divided chocolate bar:

In simple words: Take a chocolate bar with 6 pieces. Break it into one part with 4 pieces and another part with 2 pieces. Since 4 is 2 more than 2, this is correct!

Exam Tip: You can also use other numbers like 8 pieces (split into 5 and 3) or 10 pieces (split into 6 and 4) to solve this puzzle.

Question 3. These squares have been cut out from a hundreds chart fill in the empty squares.
Answer:
On a hundreds chart, numbers increase by 1 as you move right, decrease by 1 as you move left, increase by 10 as you move down, and decrease by 10 as you move up. Using these rules, we can fill in the empty squares:
 

In simple words: When you go sideways on a number chart, count by ones. When you go up or down, count by tens.

Exam Tip: Remember that moving down one box adds 10, and moving up one box subtracts 10 on a standard hundreds chart.

Question 4. Use only six seeds of any pulse for the following activity
a) Six seeds have been placed here in such a way that rectangle has 3 seeds and the triangle has 5
b) Now rearrange the 6 Rajma seeds in such a manner that there are 5 seeds in the rectangle and in the triangle
Answer:
To have exactly 5 seeds in both the rectangle and the triangle using only 6 total seeds, we must place as many seeds as possible in the overlapping region:
- Place 4 seeds in the overlapping region (where the rectangle and triangle cross over).
- Place 1 seed in the rectangle-only region (at the top).
- Place 1 seed in the triangle-only region (at the bottom).

This gives us:
- Total seeds in the rectangle: \( 1 + 4 = 5 \)
- Total seeds in the triangle: \( 4 + 1 = 5 \)
- Total seeds used: \( 1 + 4 + 1 = 6 \) seeds.

Here are the diagrams showing the initial placement and the solved rearrangement:

In simple words: To get 5 seeds in both shapes using only 6 seeds, put 4 seeds in the middle where the shapes overlap. Then put 1 seed on the top and 1 seed on the bottom.

Exam Tip: In puzzle problems with overlapping shapes, think of the overlap region as a "shared zone" that helps you save pieces.