Approximate 78 squared by following the steps below. 78 squared must lie between the whole numbers __ and __
To approximate 78 squared, we can use the pattern that if we square a number that ends in 8, the result will end in 4.
Step 1: Square the tens digit of 78, which is 7. 7 squared is 49.
Step 2: Multiply the tens digit (7) by the units digit (8), and then double the result. 7 x 8 = 56, and 2 x 56 = 112.
Step 3: Square the units digit of 78, which is 8. 8 squared is 64.
Step 4: Combine the results from steps 1, 2, and 3. 49 + 112 + 64 = 225.
Therefore, 78 squared is approximately 225.
To find the whole numbers between which 78 squared lies, we can take the square roots of the numbers that are slightly smaller and slightly larger than 78. The square root of 77 is approximately 8.775 and the square root of 79 is approximately 8.888. Therefore, 78 squared must lie between the whole numbers 8 and 9.