Four-digit addition and subtraction with thousand blocks
Add and subtract four-digit numbers in the place-value table with ones, tens, hundreds and thousands blocks, exchanging ten for one of the next place.
- Germany: grade 3
- Iran: grade 3
Guide
We build four-digit numbers from thousand, hundred, ten and one blocks and write each digit under its column.
In addition, add each column. If a column reaches ten or more, exchange ten for one of the next place.
In subtraction, if a column does not have enough, break one block from the column on the left into ten of this column, even when that column is zero: then you borrow from further left.