Question

Rohan used the model below to show 1.38÷3
.

Three groups of cubes are shown with 4 groups of tens and 3 ones in each group.

Part A
Rohan made an error in his model. Explain his error. Include the correct grouping for the model.

(1 point)

Question 2
(1 point)
Part B
What is the quotient of 1.38÷3
written as a decimal? Enter your answer in the box.

Answer 1

Part A — error and correct grouping
Rohan tried to put equal whole “ones” in each of the three groups. But 1.38 has only one whole, so you cannot give each group a whole one. You must regroup the 1 one into tenths, then divide place by place:

1 one → 10 tenths. Combine with the 3 tenths already there to get 13 tenths. 13 tenths ÷ 3 = 4 tenths each with 1 tenth left over. Convert that leftover tenth into hundredths: 1 tenth = 10 hundredths, add the 8 hundredths → 18 hundredths. 18 hundredths ÷ 3 = 6 hundredths each.

So each of the three groups should have 0 ones, 4 tenths, and 6 hundredths.

Part B — quotient
1.38 ÷ 3 = 0.46