Math worksheet for adding 10, 100, and 1000, featuring number pyramids to complete by counting.

Let's solve each part of the worksheet step by step. The goal is to fill in the missing numbers by counting up or down by 10, 100, or 1000 as indicated.

---

🔹 Understanding the Pattern

- Count by 10: Add or subtract 10 from each number.
- Count by 100: Add or subtract 100.
- Count by 1000: Add or subtract 1000.

We need to determine whether we're going up (increasing) or down (decreasing) based on the given numbers.

---

## ✔ Part a) Count by 100

Given:
```
?
?
2898
?
?
3298
```

We see that 2898 and 3298 are both present, and we're counting by 100.

Let’s find the pattern:

- From 2898 to 3298 = +400 → so there are 4 steps of 100 between them.

So let’s count upward from 2898:

- 2898 + 100 = 2998
- 2998 + 100 = 3098
- 3098 + 100 = 3198
- 3198 + 100 = 3298 ✔

Now fill in the blanks above and below 2898:

- Below 2898: 2898 - 100 = 2798
- Below that: 2798 - 100 = 2698

So the full stack (top to bottom):

1. 2698
2. 2798
3. 2898
4. 2998
5. 3098
6. 3198
7. 3298

✔ Answer for a):
```
2698
2798
2898
2998
3098
3198
3298
```

---

## ✔ Part b) Count by 1000

Given:
```
2078
?
?
?
6078
?
?
```

We have 2078 at the top and 6078 somewhere in the middle.

Let’s see how far apart they are:

- 6078 - 2078 = 4000

Since we’re counting by 1000, this means there are 4 steps of 1000 between them.

So starting from 2078, add 1000 each time:

- 2078 + 1000 = 3078
- 3078 + 1000 = 4078
- 4078 + 1000 = 5078
- 5078 + 1000 = 6078 ✔

Now continue downward from 6078:

- 6078 + 1000 = 7078
- 7078 + 1000 = 8078

But wait — the stack has 7 blocks total. Let’s list them from top to bottom:

1. 2078
2. 3078
3. 4078
4. 5078
5. 6078
6. 7078
7. 8078

✔ So the filled stack is:

```
2078
3078
4078
5078
6078
7078
8078
```

---

## ✔ Part c) Count by 10

Given:
```
?
?
3698
?
?
3728
```

We are counting by 10, and we know:

- 3698 and 3728 are two numbers in the stack.

Difference: 3728 - 3698 = 30 → so there are 3 steps of 10 between them.

So from 3698 to 3728:

- 3698 + 10 = 3708
- 3708 + 10 = 3718
- 3718 + 10 = 3728 ✔

Now go upward from 3698:

- 3698 - 10 = 3688
- 3688 - 10 = 3678

And downward from 3728:

- 3728 + 10 = 3738
- 3738 + 10 = 3748

Now list all 7 blocks from top to bottom:

1. 3678
2. 3688
3. 3698
4. 3708
5. 3718
6. 3728
7. 3738
8. 3748 ← Wait! There are only 6 blocks shown? Let's check.

Wait — looking at the image, it shows 6 blocks in column c), but only two numbers given.

Let me recount:

From top to bottom:

1. ?
2. ?
3. 3698
4. ?
5. ?
6. 3728

So 6 blocks.

We already have:

- Block 3: 3698
- Block 6: 3728

So between 3698 and 3728: 3 steps → 3708, 3718

Then:

- Above 3698: 3688, 3678
- Below 3728: 3738

So:

1. 3678
2. 3688
3. 3698
4. 3708
5. 3718
6. 3728

✔ Answer for c):
```
3678
3688
3698
3708
3718
3728
```

---

## ✔ Part d) Count by 1000

Given:
```
?
?
4173
?
?
7173
?
?
9173
```

Wait — actually, looking closely:

The stack has:

- Top: ?
- Then: ?
- Then: 4173
- Then: ?
- Then: 7173
- Then: ?
- Then: ?
- Then: 9173

So 8 blocks total.

We are counting by 1000.

Let’s analyze:

- 4173 → 7173 = +3000 → 3 steps of 1000 → so 4173, 5173, 6173, 7173
- 7173 → 9173 = +2000 → 2 steps → 7173, 8173, 9173

Now build the full sequence:

From top to bottom:

- Start from above 4173: go backward by 1000
- 4173 - 1000 = 3173
- 3173 - 1000 = 2173

Then:

- 2173
- 3173
- 4173
- 5173
- 6173
- 7173
- 8173
- 9173

✔ So the full stack:

```
2173
3173
4173
5173
6173
7173
8173
9173
```

---

## ✔ Part e) Count by 100

Given:
```
?
?
2087
?
?
2287
?
?
2587
```

Stack has 8 blocks.

We are counting by 100.

Given numbers:

- 2087
- 2287
- 2587

Check differences:

- 2287 - 2087 = 200 → 2 steps of 100 → so 2087, 2187, 2287
- 2587 - 2287 = 300 → 3 steps → 2287, 2387, 2487, 2587

Now build full sequence from top to bottom:

Start from 2087 and go upward:

- Before 2087: 2087 - 100 = 1987
- Before that: 1887

So:

1. 1887
2. 1987
3. 2087
4. 2187
5. 2287
6. 2387
7. 2487
8. 2587

✔ Answer for e):
```
1887
1987
2087
2187
2287
2387
2487
2587
```

---

✔ Final Answers Summary:

#### a) Count by 100:
```
2698
2798
2898
2998
3098
3198
3298
```

#### b) Count by 1000:
```
2078
3078
4078
5078
6078
7078
8078
```

#### c) Count by 10:
```
3678
3688
3698
3708
3718
3728
```

#### d) Count by 1000:
```
2173
3173
4173
5173
6173
7173
8173
9173
```

#### e) Count by 100:
```
1887
1987
2087
2187
2287
2387
2487
2587
```

---

📝 Explanation Recap:

- Always look at the given numbers and the step size (10, 100, or 1000).
- Determine if you're counting up or down.
- Use addition/subtraction to fill in the gaps.
- Ensure the sequence increases/decreases consistently by the required amount.

Let me know if you'd like a printable version or visual guide!