Common Multiple Lab
Mix two trails of multiples. Find the first place they meet!
1. Make both trails. Pick tool A or B, then tap each multiple in the grid. Tap again with the same tool to remove its mark.
2. Find the first meeting. A + B makes a red AB square. Switch to “Choose LCM” and tap the smallest common multiple.
A = yellow · B = green · AB = red stripes, common to both. Marks stay when you change grids. Use Tab and Enter or Space to select a square.
Investigation complete!
Lab notebook: tips and achievements
The lowest common multiple (LCM) is the smallest positive number that is a multiple of both numbers. Keep going beyond the first five multiples if the trails have not met.
For equal numbers, use both tools on that number: it belongs to both trails. Zero is excluded because we are finding the smallest positive common multiple.
To prove “lowest”, mark every multiple in both trails up to your answer. You do not need to fill the entire grid.
Earn 100 points for a solved round, plus 20 for no mistakes. A mistake breaks your streak, but you can always try again. Earn Trail Explorer for finishing, Clean Sweep for sixteen rounds with no mistakes, and Beyond 100 for solving the worksheet challenge.
Based on page 5, question 3 of the Number Revision Worksheet. Scores and badges are stored only in this browser, without names. You can play without storage.