private DIGIT handleTEENS(double d) {
		DIGIT digit = DIGIT.TEENS;


		if (d == 0.0) {
			operandValue *= 10;
			digit = DIGIT.ZERO;
		} else if (units.contains(d)) {
			operandValue *= 10;
			operandValue += d;
			digit = DIGIT.UNITS;
		} else if (teens.contains(d)) {
			operandValue *= 100;
			operandValue += d;
		} else if (tens.contains(d)) {
			operandValue *= 100;
			operandValue += d;
			digit = DIGIT.TENS;
		} else if (d == 100.0) {
			operandValue *= d;
			digit = DIGIT.HUNDRED;
		} else if (greaterThanHundreds.contains(d)) {
			operandValue *= d;
			digit = DIGIT.GREATER_THAN_HUNDREDS;
		} else {
			operandValue = Double.parseDouble("" + operandValue + (int)d);
			digit = DIGIT.UNITS;	// All other numbers can be appended and treated as a sequence of units
		}

		return digit;
	}