Answer:
the answer is 4800
Answer:
What is mental math?
Mental math is definitely what it sounds like—doing math in your head. But it’s also more nuanced than that. Being good at mental math tricks doesn’t mean that you’re able to solve 8974387 x 396 in your head instantly; while cool, that wouldn’t be very practical for daily life. So what does mental math mean?
It really just means being able to calculate in your head. It doesn’t mean you can solve every type of problem every time, nor is it a skill that you either “have” or “don’t have”; it’s a skill that you can learn, practice, and improve so that you can solve a bigger range of problems. And mental math certainly doesn’t have to be entirely in your head, either. Jotting down the numbers you need to remember to give you a head start (no pun intended), or writing down your solutions at each “step,” does not negate the “mental”-ness of the math.
Is mental math useful?
Ask this question again next time you’re trying to figure out a tip or doing any kind of construction or home improvement project! And, in addition to handy practical uses, knowing how to do mental math can also just keep your brain sharp and curb your reliance on calculators. Because, come on, doesn’t it feel good to reach for a calculator only to realize, “Wait, I don’t need it!” and figure out the answer in your head? (Spoiler: It does!) Not to mention knowing how to mentally solve small, simple math problems can save you some steps and help you out if you do need to solve a more complicated, difficult problem. There are always going to be some math problems that it would be silly to not solve with a calculator, but, yes, mental math is useful. And if you’re wondering if math itself is useful, math lessons you’ll actually use in real life.
Step-by-step explanation:
Salena needs to purchase 9 skirts for a new job. her friend, Jamie goes with her each of the skirts costs $41. Salena says that she can find the total cost by multiplying 9 and 4 and adding that to product of 9 and 1. Jamie disagrees and says that she needs to find the product of 9 and 40 and add that to the product of 9 and 1. Who is correct and why?
Answer:
Jamie is correct. This is because 41 is a combination of 40 and 1. Salena thinks that the 4 is just a 4, however, the 4 is in the tens place, so the 41 without the 1 is 40. The answer to this 41 times 9 is 369. Not 45.
Step-by-step explanation:
Each skirt is $41
Salena needs 9
(9*40) + (9*1)
360 + 9
$369
BI
Challenge 2
A: Can you find the
area of the circle?
r=x +1
B: Can you find the
circumference of
the circle?
Answer:
Area of the circle = pi * r^2 = pi * (x+1) ^ 2
Circumference of the circle = 2* pi * r = 2*pi*(x+1)
Select all the expressions that are rational numbers.
a. 3.14159…
b. –9.1234567123…
c. –9.293847210103938…
d. 227
e. –26
Answer:
d,e
Step-by-step explanation:
rational numbers are positive and negative whole numbers.
Answer:
d,e
Step-by-step explanation:
(-8) X 2/3 i NEED the answer help me
-5.33333333333
I used a calulator can I get brainliest please