LESSON 1.4
Name
Benchmark Numbers
You can use a known number, called a benchmark,
to help you estimate another number that is difficult
to count or measure.
• Is the tree about 20 or about 200 feet tall?
You know that the man is 6 feet tall.
So, 6 is the benchmark.
Look at the tree. It looks like it is a little more
than 3 times as tall as the man.
Think: 3 × 6 = 18
6 ft
So, the tree is about 20 feet tall.
Use the benchmark to decide which is the more
reasonable estimate for the unknown amount.
Circle that number.
1.
number of beans in jar
2.
pounds of potatoes in the box
50 beans
30 lb
100
3.
or
200
gallons of water in the pool
100
4.
or
1,000
paper clips in the container
© Harcourt
200 clips
400 gallons
800
RW4 Reteach
or
1,200
100
or
1,000
LESSON 1.4
Name
Benchmark Numbers
You can use a known number, called a benchmark,
to help you estimate another number that is difficult
to count or measure.
• Is the tree about 20 or about 200 feet tall?
You know that the man is 6 feet tall.
So, 6 is the benchmark.
Look at the tree. It looks like it is a little more
than 3 times as tall as the man.
Think: 3 × 6 = 18
6 ft
So, the tree is about 20 feet tall.
Use the benchmark to decide which is the more
reasonable estimate for the unknown amount.
Circle that number.
1.
number of beans in jar
2.
pounds of potatoes in the box
50 beans
30 lb
100
3.
or
200
gallons of water in the pool
100
4.
or
1,000
paper clips in the container
© Harcourt
200 clips
400 gallons
800
RW4 Reteach
or
1,200
100
or
1,000