Class 1 math puzzle worksheet with number addition challenges.

Let's solve this puzzle step by step.

Rule Given:

> The numbers in the circles added together make the number in the linking rectangle.

This means:
- The sum of two circle numbers equals the rectangle number connected to them.
- Each triangle has:
- One top circle (top node)
- Two bottom circles (left and right)
- Three rectangles connecting them:
- Top rectangle: connects top circle to left and right
- Left rectangle: connects top and left circle
- Right rectangle: connects top and right circle
- Bottom rectangle: connects left and right circles

But from the structure, it seems like:
- The top rectangle is the sum of the top circle and bottom-left circle
- The right rectangle is the sum of the top circle and bottom-right circle
- The bottom rectangle is the sum of the bottom-left and bottom-right circles

Wait — actually, looking at the diagram:

Each triangle has:
- A top circle
- Two bottom circles (left and right)
- Three rectangles:
- One on the left side, between top and bottom-left
- One on the right side, between top and bottom-right
- One on the bottom, between the two bottom circles

And the rule says:
> "The numbers in the circles added together makes the number in the linking rectangle."

So each rectangle is the sum of the two circles it connects.

Let’s go through each triangle one by one.

---

## 🔹 Triangle 1:

```
6
/ \
? 10
/ \
9 4
```

We know:
- Top circle = 6
- Bottom-left circle = 9
- Bottom-right circle = 4
- Right rectangle = 10 → connects top (6) and bottom-right (4)

Check:
6 + 4 = 10 ✔ → Correct.

Now, left rectangle connects top (6) and bottom-left (9):
So left rectangle = 6 + 9 = 15

Bottom rectangle connects bottom-left (9) and bottom-right (4):
So bottom rectangle = 9 + 4 = 13

So missing values:
- Left rectangle: 15
- Bottom rectangle: 13

✔ Done with first triangle.

---

## 🔹 Triangle 2:

```
?
/ \
12 ?
/ \
5 10
```

Given:
- Bottom-left = 5
- Bottom-right = 10
- Left rectangle = 12 → connects top and bottom-left

So:
Left rectangle = top + bottom-left →
12 = top + 5 → top = 12 - 5 = 7

Now, right rectangle = top + bottom-right = 7 + 10 = 17

Bottom rectangle = bottom-left + bottom-right = 5 + 10 = 15

So missing values:
- Top circle: 7
- Right rectangle: 17
- Bottom rectangle: 15

✔ Done with second triangle.

---

## 🔹 Triangle 3:

```
8
/ \
12 15
/ \
? ?
```

Given:
- Top = 8
- Left rectangle = 12 → connects top and bottom-left →
So: 8 + bottom-left = 12 → bottom-left = 12 - 8 = 4

Right rectangle = 15 → connects top and bottom-right →
8 + bottom-right = 15 → bottom-right = 15 - 8 = 7

Bottom rectangle = bottom-left + bottom-right = 4 + 7 = 11

So missing values:
- Bottom-left circle: 4
- Bottom-right circle: 7
- Bottom rectangle: 11

✔ Done with third triangle.

---

## 🔹 Triangle 4:

```
?
/ \
13 11
/ \
5 ?
```

Given:
- Bottom-left = 5
- Left rectangle = 13 → connects top and bottom-left →
So: top + 5 = 13 → top = 13 - 5 = 8

Right rectangle = 11 → connects top and bottom-right →
So: 8 + bottom-right = 11 → bottom-right = 11 - 8 = 3

Bottom rectangle = bottom-left + bottom-right = 5 + 3 = 8

So missing values:
- Top circle: 8
- Bottom-right circle: 3
- Bottom rectangle: 8

✔ Done with fourth triangle.

---

✔ Final Answer Summary:

#### Triangle 1:
- Left rectangle: 15
- Bottom rectangle: 13

#### Triangle 2:
- Top circle: 7
- Right rectangle: 17
- Bottom rectangle: 15

#### Triangle 3:
- Bottom-left circle: 4
- Bottom-right circle: 7
- Bottom rectangle: 11

#### Triangle 4:
- Top circle: 8
- Bottom-right circle: 3
- Bottom rectangle: 8

---

🟩 Completed Puzzle:

```
6 7 8 8
/ \ / \ / \ / \
15 10 12 17 12 15 13 11
/ \ / \ / \ / \
9 4 5 10 4 7 5 3
\ / \ / \ /
13 15 11 8
```

(Note: The bottom rectangle is drawn between the two bottom circles.)

---

✔ All missing numbers are found!