lesson

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If two bakers read the exact same recipe card, could one end up baking a giant five-pound cake while the other bakes a tiny cookie?
Take the mixed expression 2.5+21βΓ4. If you add first, you get 12, but if you multiply first, you get 4.5!
To keep calculations consistent, mathematicians rely on the order of operations β a set ranking that tells us which operation gets solved first.
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When an expression mixes fractions and decimals, we face an extra puzzle: should we turn everything into decimals, or everything into fractions?
Choosing Team Decimal
If every fraction in your problem turns into an easy decimal like 21β=0.5 or 43β=0.75, switching everything to decimals is often the fastest route.
Let's solve (0.75+21β)Γ4β1.2 using this decimal strategy.
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Parentheses came first, so converting 21β to 0.5 let us add cleanly to get 1.25 inside the grouping.
Next, multiplication beat subtraction, giving 1.25Γ4=5, and final subtraction yielded 3.8.
A common trap here is calculating 4β1.2 first because subtracting whole numbers looks easy, but multiplication always takes priority over subtraction.
What happens when a fraction refuses to turn into a tidy decimal, like 31β which becomes 0.333β¦ forever?