Binary number 101110110 is equal to decimal number _______.

The correct answer is C, 374. A binary number is written with only the digits 0 and 1, and each place stands for a power of two. Reading 101110110 from the right, the places are worth 1, 2, 4, 8, 16, 32, 64, 128 and 256. The digit 1 appears in the places worth 2, 4, 16, 32, 64 and 256. Adding those gives 2 plus 4 plus 16 plus 32 plus 64 plus 256, which is 374. A quick check helps: the number ends in 0, so it must be even, and it has nine digits, so it lies between 256 and 511. A, B and D are wrong because 468, 412 and 326 are the sums you get if you drop a place value or add a wrong one; none of them matches the set of ones in the given number. Exam tip: write the place values 1, 2, 4, 8, 16, 32, 64, 128, 256 above the digits and add where a 1 stands.