Finding 15% of 80

Pre-Algebra · Axiom Academy

Three reliable ways to compute a percentage — decimals, mental math, and a proportion. Find of 80 . We will work it three different ways and confirm they all agree. Nice work — you found of 80 three different ways and every route landed on the same number. Decimal method: Turn into 0.15 and multiply — quick when a calculator is handy. Break it down: , and is easy to find, so this is great for mental math. Proportion: cross-multiplies cleanly — reliable and shows all your work. Same answer every time: of 80 = 12 . Pick the route that fits the numbers. Handy mental shortcuts: is a divide by 10 , is half of that, is a divide by 4 , and is half.

This is the written version of the interactive lesson above. See the full Pre-Algebra course.