My 5th grader repeatedly makes this erro

Answer

I'll help you organize this into the notebook. Both errors share the same root cause (forgetting to add the decimal places from both factors), so they belong on **one card**, not two.

Let me first check what's due today, then save the card.

The notebook already has 13 cards due today (from prior sessions) — but for **tonight's new entry**, both your daughter's decimal errors share the same cause, so they go on **one card**.

Saving the card now:

Let me check the review format briefly so the parallel problem follows the self-test pattern:

Saved. Here's the card and tonight's parallel problem.

**Card saved** (one card, both errors share the same cause):

| field | value |
|---|---|
| prompt | `3.2 × 0.4 =` |
| wrong | `12.8` |
| right | `1.28` |
| tag | `decimal-multiplication-places` |
| cause | did not add decimal places from both factors (1+1=2); only counted one. Same pattern: 1.5 × 0.03 → wrote 0.45, should be 0.045 (1+2=3). |

Her 1.5 × 0.03 mistake is folded into this card via the cause — same Denkfehler, one card. The card will come back for review on the `[1, 3, 7, 14, 30]`-day ladder.

---

### Tonight's parallel problemHand this to her — let her work it from memory, no peeking at the answer below.

> **2.4 × 0.6 = ?**

(Steps she should follow: multiply 24 × 6 = 144, then count the decimal places in **both** numbers — 2.4 has 1, 0.6 has 1, total 2 — and place the decimal.)

---

### Answer + repair (only after she's tried)

**Answer: 1.44**

If she gets `14.4` → she counted1 place instead of 2 (same error as her 3.2 × 0.4 mistake).
If she gets `0.144` → she counted 1 extra place (over-corrected; rarer but worth noting).

**epair:** Write "places: 1 + 1 = 2" next to the problem before multiplying. The habit is *add first, then place the decimal last*.

**Same-type extra (3 places, like her 1.5 × 0.03 error):**

> **4.3 × 0.05 = ?**

Worked: 43 × 5 = 215. 4.3 has 1 place, 0.05 has 2 → 1+2 = **3 places**. Answer: **0.215**.