Why does my child use ≥ for a dashed line?
Your child mixes up whether the line is part of the region: a dashed line means < or >, and a solid line ≤ or ≥.
Why children do it
Shading the right side is the hard part, so the line's style is easy to overlook. But it matters: a dashed line means the points on it aren't in the region, as for y > 2x − 1, and a solid line means they are, as for y ≥ 2x − 1. Checking one point on the line itself shows which.
How to help at home
Ask them to check a point on the line itself: is it in the region? Dashed means no, solid means yes.
The right way
The point (2, k) is in the region y > 3x + 1. What is the smallest whole number k can be?
- 3 × 2 + 1 = 7On the line, y = 7 when x = 2.
- 8y must be more than 7, so the smallest whole number is 8.
Find out where your child is
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