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How to subtract tens from two-digit numbers Bill and Bernie use labelled balloons to show subtractions of 10 from several two-digit numbers which are less than 100. Bernie thinks of a number and Bill ...

Korean children's ability to solve addition problems with sums of 10, single-digit addition problems with sums between 10 and 18, and single-digit subtraction problems with minuends between 10 and 18 ...

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