Digit Problems & Place Value
Section: Number PropertiesBank code: NUM-DPVGRE frequency: MediumPro
1. Core Idea
A digit is one of 0-9. A number is built from digits by place value:
A two-digit number with tens digit a and units digit b equals 10a + b, not ab.
Writing that expansion is the first move in every digit problem. Once you do, digit puzzles become ordinary algebra with the extra constraint that each digit is an integer from 0 to 9.
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