Question

Gustav is using front-end estimation. In estimating seventy-two point nine three minus thirty-two point zero seven, Gustav follows the steps below. Where did he go wrong?

Step 1: seventy-two minus thirty-two equals forty
Step 2: zero point nine three minus zero point zero seven is approximately equal to one
Step 3:forty minus one equals thirty-nine
Step 4: seventy-two point nine three minus thirty-two point zero seven is approximately equal to thirty-nine

Step 1

Step 2

Step 3

Step 4

Answer 1

@Chineseboy15

Answer 2

@texaschic101

Answer 3

72.93 - 32.07

72 - 32 = 40
0.93 - 0.07 = .86 (close to 1)
40 - 1 = 39
72.93 - 32.07 = 40.86 (it approximately equal to 40, not 39)

step 4 is incorrect