common core 3rd grade 3.nf.3 4th grade 5th grade 3.nf.1 6th grade 6.ns.1 4.nf.3 5.nf.1 5.nf.7 decimals 4.nf.1 5.nf.2 6.ns.4 2nd grade geometry 2.g.3 3.nf.2 4.nf.2 6.rp.3 proportions 4.nf.6 1st grade 1.g.3 percents teague 3rd grd 5.nbt.5 division 6.ns.2 3.g.2 4.nf.5 8th grade 8.ns.a.1