Skip to main content
LessonsCatch the Flaw

Lesson 02 · Maths · Division with remainders

Step 1 of 4

Find the wrong step

Collectible cards being shared into four colorful prize boxes
Your lessonDivision with remaindersWarm-up

The Tournament Prize Packs

At a trading-card tournament, 157 glow cards must be shared equally among six finalists. Any true leftovers go into a lucky-draw box.

Glow cards
157 cards
Finalists
6 equal prize packs

Your question

How many cards go in each pack, and how many are left over?

Lumi’s answer: “Each finalist gets 25 cards, with 7 left over.”

1

Step 1 of 4

Find the wrong step

Find where the reasoning first breaks

Start with Step 1 and move downward. Choose the first line that stops making sense.

Later lines may be wrong too. Pick the first mistake.

Lumi’s work

These lines form one solution. Read them from top to bottom.

  1. 1

    Give each finalist 20 cards: 6 × 20 = 120, leaving 37.

  2. 2

    Give each finalist 5 more: 6 × 5 = 30, leaving 7.

  3. 3

    Stop because the remainder 7 is smaller than the quotient 25.

  4. 4

    So 157 ÷ 6 = 25 remainder 7.