Texas Math Models

Try “number line” or “4.5D”

Number line

2.45 + 1.8 = 4.25 Grade 4

jump the whole first, then the tenths 22.533.544.5 + 1 + 0.8 2.453.454.25 each small tick is one tenth · 2.45 sits halfway between 2.4 and 2.5 2.45 + 1.8 = 4.25

How this one works

How

start at 2.45, jump the whole number first, then the tenths.

Best when

you like counting up in your head.

seen one of these on a test? See it on a real question: TEKS 4.4A, adding and subtracting decimals, or TEKS 4.2G, decimals and fractions that mean the same thing.

The same problem, other ways