while waiting in the checkout line at the grocery store you add the prices up of your 3 items to make sure you have enough money.explain how to use mental math and the properties of addition to find the total costs of 3 items if the prices are $1.85, $2.74, $4.15. find the total costs.
185+415 = 200+400 = 600
It is easy to add 600+274 in your head
Using mental math, I'd add 2 + 3 + 4 to estimate that the purchase total about $9.00.
To find the total cost of the three items using mental math and the properties of addition, follow these steps:
1. Start by adding the units place of all three numbers. In this case, the units places are 5, 4, and 5 respectively. Adding them together gives us 5 + 4 + 5 = 14.
2. Next, add the tenths place of all three numbers. In this case, the tenths places are 8, 7, and 1 respectively. Adding them together gives us 8 + 7 + 1 = 16.
3. Finally, combine the sums from step 1 and step 2. The units sum is 14 and the tenths sum is 16. Combining them gives us 14 + 16 = 30.
Therefore, the total cost of the three items is $30.
Using the properties of addition, we can add the numbers in any order. This means that it doesn't matter which order you add the prices, the sum will remain the same. In this specific case, we added the prices from left to right, but you can also add them from right to left or in any other order.