Term
Right Distributivity of Divsion over addition 

Definition
Whenever the 3 quotients are whole numbers: (a+b) / c = (a/c) + (b/c) 


Term

Definition
numbers whose sums, differences, products or quotients are easy to calculate mentally. ex: 86 + 14 = 100; 600/30 = 20 


Term

Definition
The process of reformulating a sum, difference, product or quotient to one that is more readily obtained mentally. 


Term
Additive Compensation (for addition) 

Definition
Ex: 98 + 59 = 157
+2 2
100 + 57 = 157 


Term
Equal Compensation (for subtraction) 

Definition
Ex: 47  29 = 18
+1 +1
48  30 = 18 


Term
Multiplicative Compensation 

Definition
Ex: 48 * 5 = 240 /2 *2
24 * 10 = 240 


Term

Definition
Ex: 342 + 136 = 478 300 + 100 = 400 40 + 30 = 70 2 + 6 = 8 


Term

Definition
Ex: 100 * 1000 = 100,000
10^{4} * 10^{5} = 10^{9 }
20 * 30 = 600 


Term
Multiplying by Special Factors 

Definition
Numbers such as 5, 25, 99
Ex: 38 * 5 = 190
*2
38 * 10 = 380
/2
190 


Term

Definition
process of finding an approximate (estimate) to a computation, using mental math 


Term

Definition
Using a low value and high value to find a range
EX: 257 + 576 = ?
200 + 500 = 700
300 + 600 = 900
Range is from 700  900 


Term

Definition


Term
OneColumn Frontend Estimation Method 

Definition
Always provides the low estimate in addition & multiplication
EX: 498 + 251 = ?
400 + 200 = 600 


Term
TwoColumn Frontend Estimation Method 

Definition
Uses the low estimate of the ten's position, a closer estimation
EX: 498 + 251 = ?
490 + 250 = 740 


Term
Frontend with Adjustment 

Definition
EX: 498 + 251 = ?
400 + 200 = 600
98 + 51 = 100 + 50
750 


Term

Definition
3 Types  Range Estimation, OneColumn/Two Column 


Term

Definition
EX: 473 rounded down 470; rounded up 480 


Term
Truncate (aka Rounding Down) 

Definition
"to cut off" EX: 1276 truncated to 1200 


Term

Definition


Term

Definition
EX: 545 rounded to 540, not 550 (4 is even) 


Term
Round to Compatible Numbers 

Definition
EX: 26 * 37 > 25 * 40 = 1000 


Term
Arithmetic Logic  calculators 

Definition
the calculator performs operations in the order they are entered 


Term
Algebraic Logic  calculators 

Definition
the calculator evaluates expressions according to the usual mathematical convection for order of operations 


Term
Parentheses  calculators 

Definition
used for order of operations in algebraic calculators 


Term
Constant Functions  calculators 

Definition
repeated operations on calculators 


Term
Exponent Keys  calculators 

Definition
Three common exponenet keys:
x^{2} = 3^{2} enterd as 3 "x^{2}"
x^{y} = 7^{3} entered as 7 "x^{y}" 3
^ = 7^{3} entered as 7 "^" 3 


Term
Memory Functions  calculators 

Definition
stores numbers in calculators memory for future use 


Term
Scientific Notation  calculators 

Definition
2.3 x 10^{1} shows as "2.3E^{1}" in calculator 

