📏 A whole stretch
How many answers can □ + 3 < 10 have?
□ + 3 = 10 has one answer: 7. So what goes in the box when the = turns into <? Let’s test every number and see which ones light up.
Start testing ↓Not one answer: a stretch of answers.
Press Next step. Watch the bars and the number line.
📏 Number line testerStep 1 of 6
“□ + 3 = 10 is 7, so □ + 3 < 10 is 7 too!”
7 makes it equal, not less.
And every number from 0 to 6 works.
And every number from 0 to 6 works.
□ =
Your turn: 5 inequality challenges
Test numbers, then mark every answer on the number line.
🎯 Challenge0 of 5 done
⭐ You saw through the trap
An inequality has a whole stretch of answers.
□ + 3 = 10one answer:
7
7
□ + 3 < 10a stretch:
0, 1, 2, 3, 4, 5, 6
0, 1, 2, 3, 4, 5, 6
12 − □ > 5take less away:
0 to 6 again
0 to 6 again
An equation like □ + 3 = 10 is true for just one number. An inequality like □ + 3 < 10 is true for a whole stretch of numbers: test them one by one and mark every one that works on a number line. The number that makes the two sides equal sits right at the edge of the stretch, but it isn’t in it, because equal isn’t less.