"These methods of tests are for the rapid determination of the maximum density and optimum moisture content of a soil sample utilizing a family of curves and a one-point determination. One-point determinations are made by compacting the soil in a mold of a given size with a 2.5-kg (5.5-lb) rammer dropped from a height of 305 mm (12 in.). Four alternate procedures are provided as follows: Method A-A 101.6-mm (4-in.) mold; soil material passing a 4.75-mm (No. 4) sieve. Sections 5 and 6. Method B-A 152.4-mm (6-in.) mold; soil material passing a 4.75-mm (No. 4) sieve. Sections 7 and 8. Method C-A 101.6-mm (4-in.) mold; soil material passing a 19.0-mm (3/4 in.) sieve. Sections 9 and 10. Method D-A 152.4-mm (6-in.) mold; soil material passing a 19.0-mm (3/4 in.) sieve. Sections 11 and 12. 1.3. The methods described herein correspond to the methods in T 99 and must be chosen accordingly; that is@ when moisture-density relationships as determined by Method C of T 99 are used to form the family of curves@ then Method C described in this procedure must be used for the one-point determination (Note 1). Note 1-Direct reference to T 99 is made throughout these test methods@ and most terminology@ apparatus@ and procedures are the same. In addition@ the concepts described herein are applicable to one-point determinations and moisture-density relationships as specified in T 180@ with appropriate apparatus and method used as required. The following applies to all specified limits in this standard: For the purposes of determining conformance with these specifications@ an observed value or a calculated value shall be rounded off ""to the nearest unit"" in the last right-hand place of figures used in expressing the limiting value@ in accordance with the rounding-off method of ASTM E29. The values stated in SI units are to be regarded as the standard."