2nd Grade Math Pattern Worksheets with Number and Letter Sequences

Let’s solve each pattern one by one. We’ll look for the rule that connects the numbers or letters, then fill in the blanks.

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Pattern 1: 1, 3, 5, __, __, __, __, __, 17

This is counting up by 2s (odd numbers):

1 → 3 → 5 → 7 → 9 → 11 → 13 → 15 → 17

✔ Missing: 7, 9, 11, 13, 15

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Pattern 2: a, A, 1, b, B, __, __, C, __

Looks like it goes: lowercase letter, uppercase same letter, number starting at 1 and going up.

So:

a, A, 1
b, B, 2
c, C, 3

Wait — after B comes two blanks, then C, then one blank.

Actually, let’s line it up:

Position: 1=a, 2=A, 3=1, 4=b, 5=B, 6=?, 7=?, 8=C, 9=?

It seems to be grouped as (letter, Letter, Number) repeating.

Group 1: a, A, 1
Group 2: b, B, ? → should be 2
Group 3: c, C, ? → but we have only “C” at position 8, so maybe group 3 starts with c? But it says “C” at position 8.

Wait — perhaps it’s alternating case and incrementing number every third item.

Let’s try this:

Items 1-3: a, A, 1
Items 4-6: b, B, 2
Items 7-9: c, C, 3

But in the problem, item 8 is “C”, which would be the second item of group 3 → so item 7 should be “c”, item 8 = “C”, item 9 = “3”

And items 6 and 7 are blank → so item 6 = 2, item 7 = c, item 9 = 3

Wait, the blanks are under positions 6, 7, and 9.

Given:
Pos 1: a
Pos 2: A
Pos 3: 1
Pos 4: b
Pos 5: B
Pos 6: ___
Pos 7: ___
Pos 8: C
Pos 9: ___

If pattern is: [lowercase], [uppercase], [number] repeated:

Then:

Group 1: pos1-3 → a, A, 1
Group 2: pos4-6 → b, B, 2
Group 3: pos7-9 → c, C, 3

Yes! So:

Pos6 = 2
Pos7 = c
Pos9 = 3

✔ Missing: 2, c, 3

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Pattern 3: ABC, 12, DEF, 34, __, __, JKL, 78, __

Look at groups:

ABC (letters), 12 (numbers)
DEF (next 3 letters), 34 (next 2-digit number?)
Then next should be GHI, 56
Then JKL, 78
Then MNO, 90?

Check:

ABC → 1st 3 letters
DEF → next 3
GHI → next 3
JKL → next 3
MNO → next 3

Numbers: 12, 34, 56, 78, 90 → increasing by 22? Or just consecutive even tens + units?

12, 34, 56, 78 → each increases by 22? 12+22=34, 34+22=56, 56+22=78, 78+22=100 → but 100 is 3 digits. Maybe just 90? Wait, 78 to 90 is +12? Not consistent.

Actually, look: 12, 34, 56, 78 — these are pairs of consecutive even numbers? 1&2, 3&4, 5&6, 7&8 → so next should be 9&0 → 90.

Yes!

So:

After DEF, 34 → next is GHI, 56
Then JKL, 78
Then MNO, 90

Blanks are after 34 (two blanks), then after 78 (one blank)

So:

First blank after 34 → GHI
Second blank → 56
Last blank after 78 → 90? But wait, the last blank is after 78, and before that is JKL, 78, then blank → so that blank should be the next pair: MNO and 90? But only one blank shown after 78.

Looking back: “ABC 12 DEF 34 ______ ______ JKL 78 ________”

So positions:

1: ABC
2: 12
3: DEF
4: 34
5: ___
6: ___
7: JKL
8: 78
9: ___

So group 3: pos5-6 → should be GHI, 56
Group 4: pos7-8 → JKL, 78
Group 5: pos9 → should be MNO? But we need both letters and number? Only one blank.

Perhaps the pattern is: [3 letters], [2-digit number], repeat.

So:

Block1: ABC, 12
Block2: DEF, 34
Block3: GHI, 56
Block4: JKL, 78
Block5: MNO, 90

But in the sequence, after 34 (block2 end), we have two blanks → that’s block3: GHI and 56
Then JKL, 78 → block4
Then one blank → that should be block5: but only one space? Maybe they want just the next number? Or next letters?

Wait, the last blank is after 78, and 78 is the number part of block4, so next should be block5: MNO and 90 — but only one blank. Perhaps they expect “MNO” or “90”? Looking at the structure, probably they want the next full block split? But there's only one blank.

Alternatively, maybe the blanks are for the missing parts between known items.

From the layout:

“ABC 12 DEF 34 ______ ______ JKL 78 ________”

So between 34 and JKL, there are two blanks → that must be GHI and 56
Then after 78, one blank → that should be the next number? But what about letters? Maybe they skipped the letters and just want the number? Unlikely.

Another idea: perhaps the letters go ABC, DEF, GHI, JKL, MNO — so after DEF is GHI, then after JKL is MNO.

Numbers: 12, 34, 56, 78, 90

So:

After 34 → GHI, 56
After 78 → 90? But where is MNO? The blank after 78 might be for 90, assuming MNO is implied? But in the sequence, JKL is given, then 78, then blank — so likely the blank is for the next number, 90, and MNO is not written because it's after? But that breaks the pattern.

Wait, let's count the elements:

The sequence has:

Item1: ABC
Item2: 12
Item3: DEF
Item4: 34
Item5: ?
Item6: ?
Item7: JKL
Item8: 78
Item9: ?

If pattern is always [letters][number], then:

Item5 should be GHI
Item6 should be 56
Item7: JKL (given)
Item8: 78 (given)
Item9: should be MNO? But then where is 90? Or item9 is 90?

That doesn't fit.

Perhaps the letters are every odd position, numbers even? Let's see:

Pos1: ABC (letters)
Pos2: 12 (num)
Pos3: DEF (letters)
Pos4: 34 (num)
Pos5: ? → should be letters → GHI
Pos6: ? → num → 56
Pos7: JKL (letters)
Pos8: 78 (num)
Pos9: ? → should be letters → MNO

But then the number 90 is missing? And the last blank is for MNO.

But in the original, after 78 there is one blank, and no more items. So probably, the pattern expects us to put GHI, 56 in the first two blanks, and for the last blank, since JKL and 78 are given, the next should be MNO and 90, but only one blank — perhaps they want 90? Or MNO?

Looking at the way it's written: "JKL 78 ________" — likely the blank is for the next number, 90, and MNO is omitted because it's understood? But that's inconsistent.

Another possibility: the numbers are 12, 34, 56, 78, 90 — so after 34 is 56, but there are two blanks before JKL. JKL is the fourth letter group, so after DEF (third group? ABC=1, DEF=2, GHI=3, JKL=4).

Let's list the letter groups:

1: ABC
2: DEF
3: GHI
4: JKL
5: MNO

Numbers:

1: 12
2: 34
3: 56
4: 78
5: 90

In the sequence:

ABC (1), 12 (1), DEF (2), 34 (2), then blanks for GHI (3) and 56 (3), then JKL (4), 78 (4), then blank for MNO (5) or 90 (5)? Since only one blank, and the previous number was 78, likely the blank is for 90, and MNO is not required because the pattern might be ending with number.

But in the first part, after letters comes number, so after JKL (letters) comes 78 (number), then next should be MNO (letters), but there's only one blank. This is confusing.

Perhaps the last blank is for the next number, 90, and we assume the letters are skipped for brevity? But that's not good.

Let's look at the actual text: "ABC 12 DEF 34 ______ ______ JKL 78 ________"

So between 34 and JKL, there are two blanks — that must be the third set: GHI and 56.

Then after 78, one blank — that should be the fifth set's number, 90, and the letters MNO are not included because the blank is only for the number? But why would they skip letters?

Another idea: perhaps the letters are fixed groups, and numbers are paired, and the blanks are for the missing numbers and letters in order.

I think the intended answer is:

After 34: GHI, 56
After 78: 90 (and MNO is implied or not needed)

But to match the pattern, let's see the very first pattern had only numbers, this has mixed.

Perhaps for consistency, the last blank is for MNO, but then 90 is missing.

I recall that in such worksheets, sometimes they expect the next item in the sequence based on position.

Let me try this: the sequence is alternating letter-group and number-pair.

So:

1: ABC
2: 12
3: DEF
4: 34
5: GHI (next letter group)
6: 56 (next number pair)
7: JKL (given)
8: 78 (given)
9: MNO (next letter group) — but then where is 90? Or perhaps 90 is not required.

But the number after JKL is 78, which is correct for group 4, so group 5 should be MNO and 90, but only one blank.

Perhaps the last blank is for 90, and MNO is not written because the worksheet might have a mistake, or perhaps in this context, they want the number.

Let's check online or standard patterns — but since I can't, I'll go with logic.

Notice that in the number sequence: 12, 34, 56, 78 — each is formed by concatenating consecutive even numbers: 1 and 2, 3 and 4, etc., so next is 9 and 0 -> 90.

And letter groups are ABC, DEF, GHI, JKL, MNO — each three consecutive letters.

So in the sequence, after 34 (which is after DEF), the next should be GHI and 56.

Then JKL and 78 are given.

Then the next should be MNO and 90, but since only one blank after 78, and 78 is the number, the blank is likely for the next number, 90, and MNO is omitted because the pattern might be considered complete with the number.

But that's asymmetric.

Perhaps the blank after 78 is for MNO, and 90 is not required because the worksheet ends there.

But let's look at the other patterns; most have multiple blanks.

Another thought: in the sequence, the items are:

- ABC (letters)
- 12 (number)
- DEF (letters)
- 34 (number)
- [blank1] -> should be letters: GHI
- [blank2] -> should be number: 56
- JKL (letters)
- 78 (number)
- [blank3] -> should be letters: MNO

Then the number 90 is not included because there's no blank for it. That makes sense if the pattern is to alternate, and the last item is letters.

In many such worksheets, they might stop at letters.

So I'll go with:

Blank1: GHI
Blank2: 56
Blank3: MNO

But then the number 90 is missing, but perhaps it's okay.

To confirm, let's see if there's a better way.

Perhaps the numbers are always after the letters, so after JKL (letters) comes 78 (number), then the next should be MNO (letters), so blank3 is MNO.

And 90 is not required for this worksheet.

I think that's reasonable.

So for Pattern 3:

Missing: GHI, 56, MNO

But let's double-check with the position.

Positions:

1: ABC
2: 12
3: DEF
4: 34
5: GHI (first blank)
6: 56 (second blank)
7: JKL (given)
8: 78 (given)
9: MNO (third blank)

Yes, that works. The number 90 would be position 10, but there is no position 10, so it's fine.

✔ Missing: GHI, 56, MNO

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Pattern 4: 1, 9, 2, 8, 3, __, 4, __, __

Look at the sequence: 1,9,2,8,3,?,4,?,?

It seems like two interleaved sequences:

Odd positions: 1,2,3,4,... → increasing by 1
Even positions: 9,8,?,? → decreasing by 1

So:

Pos1: 1
Pos2: 9
Pos3: 2
Pos4: 8
Pos5: 3
Pos6: ? → should be 7 (since 9,8,7,...)
Pos7: 4
Pos8: ? → should be 6
Pos9: ? → should be 5? But pos9 is odd, so should be next in odd sequence: after 4 is 5, but pos7 is 4, pos9 should be 5.

Let's list:

Index: 1 2 3 4 5 6 7 8 9
Value: 1,9,2,8,3,?,4,?,?

Odd indices (1,3,5,7,9): values 1,2,3,4,? → so pos9 = 5
Even indices (2,4,6,8): values 9,8,?,? → so pos6 = 7, pos8 = 6

Yes.

So:

Pos6: 7
Pos8: 6
Pos9: 5

✔ Missing: 7, 6, 5

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Pattern 5: 140, 150, 160, __, 180, __, __, __, 220

Clearly adding 10 each time.

140, 150, 160, 170, 180, 190, 200, 210, 220

✔ Missing: 170, 190, 200, 210

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Pattern 6: __, 300, 400, __, 600, __, __, __

Adding 100 each time.

So before 300 is 200
After 400 is 500
After 600 is 700, 800, 900

Sequence: ?, 300, 400, ?, 600, ?, ?, ?

So:

Pos1: 200
Pos2: 300
Pos3: 400
Pos4: 500
Pos5: 600
Pos6: 700
Pos7: 800
Pos8: 900

Blanks are pos1, pos4, pos6, pos7, pos8

✔ Missing: 200, 500, 700, 800, 900

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Pattern 7: 100, 150, __, 250, __, __, __, 450, __

Adding 50 each time.

100, 150, 200, 250, 300, 350, 400, 450, 500

Blanks: after 150, after 250 (three blanks), after 450

So:

Pos3: 200
Pos5: 300
Pos6: 350
Pos7: 400
Pos9: 500

✔ Missing: 200, 300, 350, 400, 500

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Pattern 8: 900, 800, __, 600, __, 400, __, __, __

Subtracting 100 each time.

900, 800, 700, 600, 500, 400, 300, 200, 100

Blanks: after 800, after 600, after 400 (three blanks)

So:

Pos3: 700
Pos5: 500
Pos7: 300
Pos8: 200
Pos9: 100

✔ Missing: 700, 500, 300, 200, 100

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Pattern 9: 50, 55, 60, 65, __, __, __, __, __

Adding 5 each time.

50, 55, 60, 65, 70, 75, 80, 85, 90

✔ Missing: 70, 75, 80, 85, 90

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Pattern 10: 30, 27, 24, 21, 18, 15, __, __, __

Subtracting 3 each time.

30, 27, 24, 21, 18, 15, 12, 9, 6

✔ Missing: 12, 9, 6

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Now, let's compile all answers in order.

Final Answer:

For each row, the missing values are:

Row 1: 7, 9, 11, 13, 15
Row 2: 2, c, 3
Row 3: GHI, 56, MNO
Row 4: 7, 6, 5
Row 5: 170, 190, 200, 210
Row 6: 200, 500, 700, 800, 900
Row 7: 200, 300, 350, 400, 500
Row 8: 700, 500, 300, 200, 100
Row 9: 70, 75, 80, 85, 90
Row 10: 12, 9, 6

Note: In Row 3, I assumed the last blank is for MNO, as per the alternating pattern. If the worksheet expects 90 instead, it might be different, but based on the structure, MNO fits as the next letter group.

To be precise, let's write them as per the blanks in each row.

Since the user will fill in the blanks in order, I'll list the missing values for each row sequentially.

Final Answer:

Row 1: 7, 9, 11, 13, 15
Row 2: 2, c, 3
Row 3: GHI, 56, MNO
Row 4: 7, 6, 5
Row 5: 170, 190, 200, 210
Row 6: 200, 500, 700, 800, 900
Row 7: 200, 300, 350, 400, 500
Row 8: 700, 500, 300, 200, 100
Row 9: 70, 75, 80, 85, 90
Row 10: 12, 9, 6