Example 3.17 X 4 = ?
Estimate: 3 x 4 = 12
3.17
X 4
28+ 4 ones X 7 hundredths 28 hundredths
40 4 ones x 1 tenth = 4 tenths 40 hundredths
+ 1,200 4 ones X 3 ones = 12 ones = 1,200 hundredths
1,268 hundredths = 12.68
1 Look at the example. Compare the product with the
estimate. Is it reasonable that the product is greater
than the estimate? Explain.