Polymer clays or plasticine clays are made of synthetic plastics and require âcuringâ or low heat to harden. They stay moldable for a very long time if stored properly in a plastic or metal box (no paper or fabric that would absorb the moisture). Polymer clays are usually very smooth and have a silky feeling.
On average, 4th graders are 9-10 years old because that is the normal age for the grade. But kids could potentially be anywhere from about 8 to 11 years old, since some kids hâ¦ave to repeat a year in school and get behind, and then some kids are a year ahead or have late birthdays before the cut-off date.
Report Abuse. grade 3 should be about $5.00 dollars an hour because 3 graders are young and can still learn... grade 8 should be about $10.00 -$15.00 an hour because 8th graders sometimes will need more help than eighth graders because they forget most of what they learn when they grow older..