Texas Math Models

Try “number line” or “4.5D”

The halfway mark

367 + 258 = 625 Grade 3

the midpoint decides, and a number sitting exactly on it always rounds UP past the midpointexactly on the midpoint 360370 365 367 367 is past 365, so it is nearer 370 367 ≈ 370 360370 365 365 365 sits exactly on the midpoint: round UP 365 ≈ 370 the same rule at any place: 250 ≈ 300, 4,500 ≈ 5,000

How this one works

How

find the halfway number, then see which side yours is on.

Best when

you forget which way to round.

The same problem, other ways