1 liters y and 1 liters b since the question states that you need to add
All estimating problems make the assumption you are familar with your math facts, addition and multiplication. Since students normally memorize multiplication facts for single-digit numbers, any problem that can be simplified to single-digit numbers is easily worked.
2. You are asked to estimate 47.99 times 0.6. The problem statement suggests you do this by multiplying 50 times 0.6. That product is the same as 5 × 6, which is a math fact you have memorized. You know this because
.. 50 × 0.6 = (5 × 10) × (6 × 1/10)
.. = (5 × 6) × (10 ×1/10) . . . . . . . . . . . by the associative property of multiplication
.. = 30 × 1
.. = 30
3. You have not provided any clue as to the procedure reviewed in the lesson. Using a calculator,
.. 47.99 × 0.6 = 28.79 . . . . . . rounded to cents
4. You have to decide if knowing the price is near $30 is sufficient information, or whether you need to know it is precisely $28.79. In my opinion, knowing it is near $30 is good enough, unless I'm having to count pennies for any of several possible reasons.
The answer to your question is 2/4 which is 1/2
1. - Since a cube is all the same lengths on all sides you would want to find the area of one of the sides. You would do this by multiplying 3.8 by 3.8.
3.8*3.8=14.44
Since you have six faces on a cube you want to multiply this by 6.
14.44*6=86.64
So your answer for 1. is 86.64 in^2 of glass
3. Same thing as number one. Find the face of one side:
1 1/3*1 1/3 is about 1.7777
Multiply this by the six faces.
1.7777*6 is about 10.66666
So your answer for 3. is about 10.666 (repeating) in^2
4. For this one, you want to follow the surface area formula for a cylinder. Which is - A=2πrh+2πr^2
When you put all your numbers in it would look like this:
2*3.14*2*22+2*3.14*2^2
Once you do that equation you will get 301.44
So that should be your answer 301.44 cm^2
Hope this helps!
