Texas Math Models

Try “number line” or “4.5D”

Fractions & expanded form

2.45 + 1.8 = 4.25 Grade 4

a decimal is a fraction of tenths and hundredths, written another way 2.45 = 2 + 4/10 + 5/100 1.80 = 1 + 8/10 write every tenth as ten hundredths, then they add like whole numbers 2 45/100 + 1 80/100 = 3 125/100 = 4 25/100 = 4.25

How this one works

How

write each decimal as hundredths, add them, then write it back as a decimal.

Best when

you want to know why the zero can be added.

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