PURPOSE Cell references control how formulas change when copied. RELATIVE REFERENCES A relative reference changes when copied to another row or column. Example: A1 becomes A2 when copied down. ABSOLUTE REFERENCES An absolute reference stays fixed when copied. It is often marked with dollar signs, such as $A$1. WHEN TO USE ABSOLUTE REFERENCES Use them for tax rates, conversion rates, fixed assumptions, lookup tables, or constants. TIP If a copied formula gives strange results, check whether a reference should be absolute.