Texas Math Models

Try “number line” or “4.5D”

Standard algorithm

625 − 258 = 367 G3–G4

borrow to subtract · struck = spent, red = new value borrow onceborrow across a zero 1 1 625 218 − 407 591 1 11 6025 2258 − 3767 the hundreds have nothing to give: go to the thousands

How this one works

How

stack by place value; if a place is too small, borrow ten from the place to its left.

Best when

you want the quickest way.

seen one of these on a test? See it on a real question: TEKS 3.4A, adding and subtracting to 1,000.

The same problem, other ways