With mental math, you can perform equations quickly and efficiently. They also help you to develop your own strategies and solve more complex math equations. Hope this helps;)
Answer:
The sum of 1.8 and 1.56 is 3.36 according to the model
Sum of decimals
Given the expression 1.8 + 1.56
Using the partial sum method
1.8 + 1.56 = (1.0 + 0.8) + (1.0+0.56)
Regroup as whole and decimal number
1.8 + 1.56 = (1.0 + 1.0) + (0.8 +0.56)
1.8 + 1.56 = 2.0 + 1.36
1.8 + 1.56 = 3.36
Hence the sum of 1.8 and 1.56 is 3.36 according to the model
The 3 option
(3,9), (-7,1), (6,12), (-3, -9)
The correct answer is C (-20) let me know if you want to know how I got that answer
