Otterly Hilarious subtraction worksheet using the count-up strategy for fun math practice.

Explanation:
We are given subtraction problems. For each, we need to find the answer using the count-up strategy, which means starting from the smaller number and counting up to the larger number — the number of counts is the difference.

Let’s solve each one step by step:

I: 12 − 10 = ?
Start at 10, count up to 12:
10 → 11 (1), 11 → 12 (2) → total = 2

E: 19 − 11 = ?
Start at 11, count up:
11→12 (1), 12→13 (2), 13→14 (3), 14→15 (4), 15→16 (5), 16→17 (6), 17→18 (7), 18→19 (8) → total = 8

B: 9 − 6 = ?
6 → 7 (1), 7 → 8 (2), 8 → 9 (3) → 3

R: 5 − 4 = ?
4 → 5 (1) → 1

V: 10 − 6 = ?
6 → 7 (1), 7 → 8 (2), 8 → 9 (3), 9 → 10 (4) → 4

K: 15 − 9 = ?
9 → 10 (1), 10→11 (2), 11→12 (3), 12→13 (4), 13→14 (5), 14→15 (6) → 6

R: 12 − 7 = ?
7 → 8 (1), 8→9 (2), 9→10 (3), 10→11 (4), 11→12 (5) → 5

A: 18 − 11 = ?
11 → 12 (1), 12→13 (2), 13→14 (3), 14→15 (4), 15→16 (5), 16→17 (6), 17→18 (7) → 7

N: 16 − 7 = ?
7 → 8 (1), 8→9 (2), 9→10 (3), 10→11 (4), 11→12 (5), 12→13 (6), 13→14 (7), 14→15 (8), 15→16 (9) → 9

Now collect the answers with their letters:

I = 2
E = 8
B = 3
R = 1
V = 4
K = 6
R = 5
A = 7
N = 9

So the sequence of answers (in order of the letters shown in the riddle line) is:
I, E, B, R, V, K, R, A, N → values: 2, 8, 3, 1, 4, 6, 5, 7, 9

Below the riddle: “How do otters keep their money?”
And there’s a blank line with numbered slots:
_ _ _ _ _ _ _ _ _
with numbers underneath: 2 4 8 1 3 10 9 6

Wait — actually, looking again: the bottom shows a blank riddle line with underscores, and below it numbers:
2 4 8 1 3 10 9 6

But we have 9 answers (I through N, but note: R appears twice — positions 4 and 7). The riddle likely uses the letters corresponding to the answers, and the numbers below indicate which answer (by position) goes where.

Let me re-express the problem layout clearly:

The worksheet says:
- Solve each problem; each has a letter (I, E, B, R, V, K, R, A, N)
- Then use your answers *with the problem’s letter* to solve the riddle.

The riddle line is:
“____ ____ otters keep their money?”

But in the image, it's written as:
“__ __ __ __ __ __ __ __ __ otters keep their money?” — actually, it looks like 9 blanks (one per problem), then the phrase.

Then below that, there’s a row:
2 4 8 1 3 10 9 6
But wait — that’s only 8 numbers, and we have 9 answers. Hmm — maybe the 10 is a typo or misalignment? Let’s double-check the original problem list:

There are 9 problems:
1. I
2. E
3. B
4. R
5. V
6. K
7. R
8. A
9. N

So 9 letters → 9 answers.

The bottom line shows blanks with numbers under them:
positions labeled: 2, 4, 8, 1, 3, 10, 9, 6 — that’s 8 numbers. But possibly the “10” is a mistake — or perhaps the riddle uses only 8 letters? Wait — maybe the riddle is:
“___ ___ ___ ___ ___ ___ ___ ___” (8 blanks) and the 9th answer is not used? Unlikely.

Alternatively, perhaps the numbers below indicate *which letter’s answer goes in that position*. That is, the riddle has 8 blanks, and the numbers tell you: put the answer from problem #2 in blank 1, problem #4 in blank 2, etc.

Let’s assume the bottom row is a key: the numbers (2, 4, 8, 1, 3, 10, 9, 6) refer to the *problem numbers* (1 through 9), and we map them to blanks.

But there’s no problem #10 — so “10” must be an error. Let’s look again: maybe it's “10” as in the *answer value*, not problem number? No — the formatting suggests those are positions.

Wait — better idea: In many such worksheets, after solving, you write the *letter* of the problem whose answer matches the number below each blank.

Look at the bottom: there’s a line of numbers:
2 4 8 1 3 10 9 6
and above them, blanks. The instruction says: “Use your answers with the problem’s letter to solve the riddle.”

That usually means: for each blank, find which problem has that answer, and write that problem’s letter.

Example: If a blank has “2” under it, and problem I has answer 2, then write I in that blank.

So let’s make a mapping of answer → letter(s):

Answer 1 → R (problem 4)
Answer 2 → I
Answer 3 → B
Answer 4 → V
Answer 5 → R (problem 7)
Answer 6 → K
Answer 7 → A
Answer 8 → E
Answer 9 → N

(We have no answer = 10 — so the “10” under a blank is likely a mistake, or perhaps it's “1 0” meaning two digits? But unlikely.)

Given standard version of this worksheet (known as “Otterly Hilarious”), the riddle is:
“IN THE RIVER” or similar? Wait — let’s compute the intended phrase.

Common riddle: “How do otters keep their money? — In a *river* bank!” 😄

So likely the answer is: RIVER BANK or IN A RIVER.

Let’s test using our letters and answers:

We have answers:
I=2
E=8
B=3
R=1 (first R)
V=4
K=6
R=5 (second R)
A=7
N=9

Now the bottom number line: 2 4 8 1 3 10 9 6
If we ignore “10” (maybe it's a misprint for “5”? since we have two R’s — answer 1 and 5), or perhaps the 10 is actually “1 0” split — but more likely, in the real worksheet, the numbers are: 2, 4, 8, 1, 3, 5, 9, 6 — which would correspond to:

Blank 1: answer = 2 → letter I
Blank 2: answer = 4 → letter V
Blank 3: answer = 8 → letter E
Blank 4: answer = 1 → letter R
Blank 5: answer = 3 → letter B
Blank 6: answer = 5 → letter R (second R)
Blank 7: answer = 9 → letter N
Blank 8: answer = 6 → letter K

So letters: I, V, E, R, B, R, N, K → “IVERRBNK” — doesn’t make sense.

Try different order: maybe the numbers indicate *position of the letter* in the answer string.

Alternative: Perhaps the riddle is filled by placing the letters in order of the answers sorted by the number below.

Wait — let’s search memory: This exact worksheet “Otterly Hilarious” from Lucky Little Learners has the riddle:
“IN A RIVER” — and the answer letters spell that.

Which letters give “IN A RIVER”? That’s 7 letters: I, N, A, R, I, V, E, R — 8 letters with space.

Our letters: I, N, A, R (twice), V, E, B, K — B and K don’t fit.

Let me recalculate all subtractions to be 100% sure:

I: 12 − 10 = 2 ✔
E: 19 − 11 = 8 ✔
B: 9 − 6 = 3 ✔
R (1st): 5 − 4 = 1 ✔
V: 10 − 6 = 4 ✔
K: 15 − 9 = 6 ✔
R (2nd): 12 − 7 = 5 ✔
A: 18 − 11 = 7 ✔
N: 16 − 7 = 9 ✔

All correct.

Now, the bottom has a line:
_ _ _ _ _ _ _ _
with numbers: 2 4 8 1 3 10 9 6

Since there is no answer 10, and we have answers 1–9, likely “10” is a typo and should be 5 (since 5 is missing in the list 2,4,8,1,3,?,9,6). The missing answer in that sequence is 5.

So assume the numbers are: 2, 4, 8, 1, 3, 5, 9, 6

Now match each number to its letter:
- 2 → I
- 4 → V
- 8 → E
- 1 → R
- 3 → B
- 5 → R
- 9 → N
- 6 → K

Sequence: I, V, E, R, B, R, N, K

Still not meaningful.

Wait — maybe the riddle is read as: place the *letters* in the order of the problems, and the numbers below indicate which positions to read.

Another possibility: The final question is “How do otters keep their money?” and the answer is a pun: “In a *river* bank!”
So we need the letters to spell RIVER BANK → 8 letters (R I V E R B A N K) — that’s 8 letters.

Do we have those letters? Yes: R, I, V, E, R, B, A, N, K — we have all except we have extra R.

Specifically:
R (from 5−4), I (12−10), V (10−6), E (19−11), R (12−7), B (9−6), A (18−11), N (16−7), K (15−9)

That’s 9 letters. To get “RIVERBANK” = 9 letters: R-I-V-E-R-B-A-N-K

Yes! “RIVERBANK” is 9 letters.

Let’s check:
1. R → answer 1
2. I → answer 2
3. V → answer 4
4. E → answer 8
5. R → answer 5
6. B → answer 3
7. A → answer 7
8. N → answer 9
9. K → answer 6

So if the riddle blanks are 9, and the numbers below are the *answer values* that tell you which problem’s letter to use — but the given number row is 2 4 8 1 3 10 9 6 — still off.

Given the time, and that this is a known worksheet, the intended riddle answer is:

RIVER BANK

But the blank line likely expects the letters corresponding to the answers in order of the numbers given. However, since the only consistent 9-letter phrase from our letters is RIVERBANK, and that makes sense for “how do otters keep their money? — in a river bank!”, we conclude the solved riddle is:

RIVER BANK

But the question asks: “How do otters keep their money?” and we fill the blanks with letters.

Since the user only asks to “solve the problem accurately”, and the core math is the subtraction, and then using those to get the riddle — and the final output expected is likely the riddle answer — and in all sources, the answer is:

IN A RIVER BANK — but we have no “IN A”.

Wait — look at the very bottom: it says “____ otters keep their money?” with 9 underscores, and below: numbers 2 4 8 1 3 10 9 6 — maybe the 10 is actually “1 0**” meaning two characters? Unlikely.

Given the instructions: “Use your answers with the problem’s letter to solve the riddle below.” And the only logical completion is to list the letters in the order of the answers matching the numbered blanks.

But since we must provide a final answer, and the math is definite, perhaps the expected output is the list of answers:

I=2, E=8, B=3, R=1, V=4, K=6, R=5, A=7, N=9

However, the riddle part is essential.

Let me try mapping the number line as *indices*: the first blank uses the letter of the problem whose answer is 2 → I
second blank: answer 4 → V
third: 8 → E
fourth: 1 → R
fifth: 3 → B
sixth: 10 → ??? no 10
Unless 16−7=9, 18−11=7, etc. No 10.

Wait — could 19−11 be 8, yes; what if someone misreads 19−9? No.

I think the “10” is a printing error and should be “5”. Then the sequence of letters is: I, V, E, R, B, R, N, K — still not English.

What if we order the letters by the answer value 1 to 9:

Answer 1: R
2: I
3: B
4: V
5: R
6: K
7: A
8: E
9: N

Write them in order 1 to 9: R I B V R K A E N — no.

But “R I V E R” appears if we take answers: 1(R), 2(I), 4(V), 8(E), 5(R) → R I V E R

Then remaining: 3(B), 7(A), 9(N), 6(K) → B A N K

So “RIVER BANK”

Thus, the riddle answer is: RIVER BANK

Since the question is “How do otters keep their money?”, the answer is: In a river bank!
But the blank is probably for the phrase “RIVER BANK”.

Given the format, and that the student is to fill letters, and the final output expected here is the solved riddle phrase, I will provide:

Final Answer: RIVER BANK