200 likes | 433 Views
Mind reading. Think of a number. Multiply it by 2. Add 8. Divide by 2. Subtract the number you started with. What is your answer?. Mind reading. 4. Mind reading. Think of a number. Add 3. Double it. Subtract the number you first thought of. Subtract it again. What is your answer?.
E N D
Mind reading Think of a number Multiply it by 2 Add 8 Divide by 2 Subtract the number you started with What is your answer?
Mind reading Think of a number Add 3 Double it Subtract the number you first thought of Subtract it again What is your answer?
Mind reading Everybody started with different numbers, but ended up with the same number. Why? The number you first thought of is always eventually subtracted. Everyone has performed the same operations so you all end up with the same answer.
Mind reading Think of a number n
Mind reading Multiply it by 3 3n
Mind reading Add 14 3n + 14
Mind reading Subtract the number you first thought of 2n + 14
Mind reading Divide by 2 n + 7
Mind reading Subtract the number you first thought of 7
Expressions An expression consists of one or more terms. 3n is an expression. 3n + 8 is an expression with two terms.
Think of a Number • Double it • Add 3 • Multiply by 4 • Subtract 12 • Divide by 8.
Think of a Number • Double it • Add 20 • Subtract original number • Subtract 5 • Subtract original number.
Think of a Number • Add 4 • Subtract 3 • Add 9 • Subtract original number.
Think of a Number • Add 8 • Double it • Subtract original number • Subtract 1 • Subtract original number.
Think of a Number • Add 3 • Double it • Subtract original number • Add 1 • Subtract original number.
Think of a Number • Add 2 • Treble it • Subtract original number • Halve it • Subtract original number • Add 4.
Think of a number Double it Add 3 Multiply by 4 Subtract 12 Divide by 8 n 2n 2n+3 8n+12 8n n