Estimating Decimal Sums and Differences in Grade 5

What are the two methods discussed for estimating decimal sums and differences?

• Rounding to the nearest whole number and using benchmarks

• Using fractions and percentages

• Multiplying and dividing

• Using algebraic expressions

What is the first step in the method of rounding to the nearest whole number?

• Subtract the numbers first

• Add the numbers first

• Round to the nearest whole number

• Use a number line

In the example of the singer recording a CD, what is the rounded value of 3.78 minutes?

• 2

• 5

• 4

• 3

What is the total estimated recording time for the three songs after rounding?

• 11 minutes

• 8 minutes

• 9 minutes

• 10 minutes

What is the second method for estimating decimal sums and differences?

• Using fractions

• Using benchmarks

• Using algebra

• Using percentages

What are the basic benchmarks used on the number line?

• 0, 0.2, 0.4, 0.6, 0.8

• 0, 0.3, 0.6, 0.9, 1

• 0, 0.1, 0.2, 0.3, 0.4

• 0, 0.25, 0.5, 0.75, 1

In the example problem, what is the closest benchmark to 0.22?

• 0.1

• 0.3

• 0.25

• 0.2

What is the closest benchmark to 0.76?

• 0.9

• 0.8

• 0.7

• 0.75

What is the estimated difference between 0.76 and 0.22 using benchmarks?

• 0.3

• 0.4

• 0.6

• 0.5

What should your notes include according to the teacher?

• Only the title

• Only the date

• Both the title and the date

• Neither the title nor the date