Math 1 · Lesson 1 · Identity and inverse · part 5 of 6
The hunt for hidden 1s and 0s
Three things you already know how to do.
The hunt for hidden 1s and 0s
Three things you already know how to do. Where is the 1 or the 0 hiding?
Equivalent fractions
34 = 912. Hiding: we multiplied by 33, and 33 is 1. Nothing changed; it just looks different.
Unit conversions
2 feet = 24 inches. Hiding: 2 ft x 12 in1 ft. That fraction equals 1, because 12 inches and 1 foot are the same amount.
One-step equations
x + 5 = 12, so x = 7. Hiding: we added -5 to both sides. The left side became x + 0, and the 0 is why x is now alone.
The line to remember: every time you cancel, cross out, move something to the other side, or find a common denominator, you are secretly adding zero or multiplying by one. From now on, say the secret out loud.