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.
Answer:
it's the last one *25,000 J
Step-by-step explanation:
9514 1404 393
Answer:
[[274][895][136]]
Step-by-step explanation:
Starting with the middle row, we need a product of two single-digit numbers that is between 53-1 = 52 and 53-9 = 44. Possible products are 5×9=45 and 6×8=48. This means the number in the middle position in the left column must be 8 or 5.
The middle number in the left column cannot be 5, because we must be able to get -5 by subtracting that number from a sum that is at least 3 = 1+2. So, the middle number in the left column is 8, the other two numbers in that column are 1 and 2, and the other two numbers in the middle row are 5 and 9.
There is no product of single-digit numbers that is 30-1 = 29, so the upper left number must be 2, and the bottom left number must be 1. The other two numbers on the top row must be 4 and 7, so that row's equation is 2+4×7=30.
The only remaining digits are 3 and 6. In order to have -3 on the bottom row, the equation there must be 1×3-6 = -3. Then the middle digit must be divisible by 3, so must be 9.
Our solution is ...
row 1: 2 + 7 × 4 = 30
row 2: 8 + 9 × 5 = 53
row 3: 1 × 3 - 6 = -3
And that makes the column equations be ...
col 1: 2 - 8 + 1 = -5
col 2: 7 + 9 / 3 = 10
col 3: 4 × 5 - 6 = 14
Answer:
18
Step-by-step explanation:
1.80 x 10 = 18.0
:)
Answer: the numbers were negative so he needed to add the positive numbers to that equation (I think sorry if I’m wrong)
Step-by-step explanation:
