# A fictional paper store


## Complete neutral source

An imagined paper store starts with 704 cards and uses 168 cards once. Find the cards left. This is a different opportunity after teaching, not an equal-difficulty test form or a progress measure.

## Eligibility

After subtraction with regrouping and inverse checks have actually been taught, e.g. Day 54. Teaching this source makes its later use exposed; receive supported work honestly.

## Access and help

Read or sign the exact source and prompts neutrally, enlarge them, or scribe the learner’s chosen words. A figure, operation, regrouping, equation role or check supplied by an adult is mathematical help and is recorded as such. Show, draw, type, sign or use usual communication. One component can be enough; pause/pass/finish are choices. Four own spaces are genuinely empty. Models, criteria and next lessons stay on separate staff pages.

## First later limit

First/later are opportunity labels, not fixed order, matches, calibrated difficulty or learning gain. If source/answer exposed, record that rather than claim unseen.

## Prompts


1. What does each count mean, and what number sentence finds cards left?

2. Find cards left using a strategy you can show.

3. A made-up note says “subtract each smaller digit from each bigger digit, so 704−168=664”. Keep or repair this method with a reason.

4. Check your result and explain what it counts.