Rounding
2.1 The student will
b) round two-digit numbers to the nearest ten
2.6 The student, given two whole numbers whose sum is 99 or less, will
a) estimate the sum
2.7 The student, given two whole numbers, each of which is 99 or less, will
a) estimate the difference
Read Aloud Books
b) round two-digit numbers to the nearest ten
2.6 The student, given two whole numbers whose sum is 99 or less, will
a) estimate the sum
2.7 The student, given two whole numbers, each of which is 99 or less, will
a) estimate the difference
Read Aloud Books
Videos
Rounding to the Nearest Ten
Rounding to the Nearest Ten
Activities
Rolly Polly
Round Street Rounding
To play, students need 2 dice, beans or game chips, and dry erase markers. Students roll the 2 dice and create a 2-digit number. They must determine the friendly numbers on the border of their number. For example, if a player rolls a 6 and a 3, she can make the number 63. The friendly numbers on the border are 60 and 70.
Friendly numbers are written in the houses. The midpoint is written on the tree. Students fill in the rest of the number line and determine which house their number is closest to.
Once the number is rounded, students mark the table at the top. They can keep track with check marks or the beans/chips.
Rounding Tape
We start with a regular 100s chart, with an extra box on the end of each row that it labeled “tab.” This is where students will glue each row to another.
Students color code the hundreds chart by first coloring each multiple of 10 a different color. I make sure to have them keep these 10 crayons right on hand, because we will need them again.
Leave the numbers 1 through 4 blank, because these numbers round to 0.
Then students grab the color that they used on the number 10. We color the numbers 5, 6, 7, 8, 9, 11, 12, 13, and 14 the same color as the number 10. These are all the numbers that round to 10.
After doing the same with all the multiples of 10, the students cut the ROWS and glue the tabs to each other.
Every student will have a number line 1 to 100 that illustrates rounding to the nearest 10.
Rolly Polly
Round Street Rounding
To play, students need 2 dice, beans or game chips, and dry erase markers. Students roll the 2 dice and create a 2-digit number. They must determine the friendly numbers on the border of their number. For example, if a player rolls a 6 and a 3, she can make the number 63. The friendly numbers on the border are 60 and 70.
Friendly numbers are written in the houses. The midpoint is written on the tree. Students fill in the rest of the number line and determine which house their number is closest to.
Once the number is rounded, students mark the table at the top. They can keep track with check marks or the beans/chips.
Rounding Tape
We start with a regular 100s chart, with an extra box on the end of each row that it labeled “tab.” This is where students will glue each row to another.
Students color code the hundreds chart by first coloring each multiple of 10 a different color. I make sure to have them keep these 10 crayons right on hand, because we will need them again.
Leave the numbers 1 through 4 blank, because these numbers round to 0.
Then students grab the color that they used on the number 10. We color the numbers 5, 6, 7, 8, 9, 11, 12, 13, and 14 the same color as the number 10. These are all the numbers that round to 10.
After doing the same with all the multiples of 10, the students cut the ROWS and glue the tabs to each other.
Every student will have a number line 1 to 100 that illustrates rounding to the nearest 10.
Rounding Roller Coaster
Roller Coaster Rounding Video here.
The roller coaster rounding video above is a perfect jumping off point for this lesson! The most important part of using this strategy is that students do not become reliant on a rhyme or trick to round – they must add in friendly border numbers on either end of the roller coaster (similar to Round Street Rounding). This helps when they round larger numbers.
Estimation
Roller Coaster Rounding Video here.
The roller coaster rounding video above is a perfect jumping off point for this lesson! The most important part of using this strategy is that students do not become reliant on a rhyme or trick to round – they must add in friendly border numbers on either end of the roller coaster (similar to Round Street Rounding). This helps when they round larger numbers.
Estimation