Mental Math
Estimate: 1253 + 382 + 517
Low estimate: 1000 + 300 + 500 --> 1800
High estimate: 1300 + 400 + 600 -->2300
What is the following written as an exponent: 5xx5xx5xx5
5^4
Evaluate: (-5)+(-6)+(+8)
(-3)
Evaluate: 2/3+1/5
13/15
Evaluate: 7-2(3+1)^2
-25
Eva went to the store with one bill and no change in her pocket. She had enough money to buy her and 2 of her friends each a slurpee for $3.45 each. What bill did she have?
a $20!
36 xx1000
36 000
What is the value of: 3^4
81
Evaluate: (-8)-(-14)
(+6)
Evaluate: 5/6xx2/3xx1/2
10/36 or 5/18
Evaluate: 3xx2-11+6xx3xx2
31
Kaleb took his 3 friends out for dinner. He covered half of the bill and each of his other 3 friends split the rest evenly. If the total bill was $28.80, how much did each friend pay?
$4.80
20 xx 230
4600
What is the square root of 144?
12
Evaluate:
(-7)xx(+2)xx(-5)
(+70)
Evaluate: 3/5-:5/6
18/25
Evaluate: 2(2+1)^2-3^3
-9
Half of a pizza is split between 3 friends. How much of a whole pizza does he get?
1/6
Estimate: 31.7xx24.3
Low estimate: 30 x 20 --> 600
Middle estimate: 30 x 25 --> 750
High estimate: 40 x 30 --> 1200
What two perfect squares is 42 between?
36 and 49
Evaluate:
(+31)-(-11)+(-16)-(+18)
(+8)
Find the x: 6/8=21/x
28
Evaluate: (3-3(5+1))/5+4
1
The temperature started at 26 degrees today. An eruption of Mt Etna will cause a drop in temperature of 4 degrees per day for the next week. What will the temperature be 7 days from now?
Find 2 ways to estimate:
68.2-:8.6
70/10 = 7
70/7 = 10
64/8 = 8
68/10 = 6.8
...
What is the approximate value of the following (no calculators!!): sqrt42
between 6 and 7 --> about 6.5
Evaluate: (-18)-:(+3)xx(+2)
(-12)
Simplify as a mixed number: 1 3/4+2/3-1/2
1 11/12
Evaluate: sqrt(4(4-6)^2-(-7))
3
In the first game of a doubleheader, Micah scored one third of his teams 48 points. In the second game he scored 20 points. How many points did he average for the two games?
18 points per game!