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Let’s go through each number and break it down into tens and units.

Remember:
- The “tens” part is how many groups of 10 are in the number.
- The “units” part is what’s left over after taking out the tens.

We’ll do this for every number shown:

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12 → 10 + 2 (already done as an example)

19 → 10 + 9
(1 ten and 9 units)

15 → 10 + 5
(1 ten and 5 units)

14 → 10 + 4
(1 ten and 4 units)

11 → 10 + 1
(1 ten and 1 unit)

10 → 10 + 0
(1 ten and 0 units — yes, zero is okay!)

16 → 10 + 6
(1 ten and 6 units)

17 → 10 + 7
(1 ten and 7 units)

12 → 10 + 2
(same as the first one — 1 ten and 2 units)

13 → 10 + 3
(1 ten and 3 units)

18 → 10 + 8
(1 ten and 8 units)

20 → 10 + 10
Wait — hold on! 20 is two tens. But the worksheet says “break into tens and units”. In standard decomposition for early math, we usually write 20 as 20 = 10 + 10, but sometimes they expect you to think of it as 2 tens and 0 units — however, since the diagram only has two circles under each number, and the example uses 10 and 2 for 12, it seems they want you to split into one “ten” circle and one “units” circle.

But 20 doesn’t fit that pattern unless we allow the “tens” circle to be 20 and units 0? That doesn’t make sense.

Actually — looking again at the structure: each top number splits into TWO bottom circles. For 12, it’s 10 and 2. So for 20, if we follow the same logic, it should be 10 and 10? But 10 is not a “unit” — units are 0–9.

Hmm… maybe the worksheet expects us to treat all numbers from 10–19 as 10 + [units], and 20 as 10 + 10? Or perhaps 20 is special?

Wait — let’s check the pattern. All other numbers are between 10 and 19 except 20. And 20 is the last one.

In many elementary curricula, when decomposing 20 into tens and units, they might still say:
→ Tens: 20 (but that’s not right because 20 is two tens)
OR
→ They might expect: 10 + 10

But looking at the diagram — each number branches into exactly two circles. For consistency with the rest, and since 20 = 10 + 10, I think that’s what they want here — even though 10 isn’t a “unit”, in this context, they may just mean “split into two parts where one is 10”.

Alternatively — maybe they want 20 broken as 20 = 20 + 0? But that doesn’t match the example.

Let me double-check the example: 12 → 10 and 2. So the left circle is always 10 for numbers 10–19, and the right circle is the leftover.

For 20, if we follow that, it would be 10 and 10 — because 20 - 10 = 10.

Yes — that makes sense for this worksheet’s pattern. Even though 10 is not a single-digit unit, in this case, since the instruction is “break into tens and units”, and 20 has two tens, but the diagram only allows two boxes, they probably expect 10 and 10.

Some teachers accept that for 20, you can write 10 + 10 to show it’s two tens.

So I’ll go with that.

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Final breakdowns:

- 19 → 10, 9
- 15 → 10, 5
- 14 → 10, 4
- 11 → 10, 1
- 10 → 10, 0
- 16 → 10, 6
- 17 → 10, 7
- 12 → 10, 2
- 13 → 10, 3
- 18 → 10, 8
- 20 → 10, 10

All checked and consistent with the example given (12 → 10, 2).

Final Answer:
19 → 10, 9
15 → 10, 5
14 → 10, 4
11 → 10, 1
10 → 10, 0
16 → 10, 6
17 → 10, 7
12 → 10, 2
13 → 10, 3
18 → 10, 8
20 → 10, 10