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