Estimation and Compatible Numbers

The point on the number line represents the amount of money needed for the Johnson family to go on vacation to Hawaii. About how much money does the Johnson family need to go on vacation?

• The Johnson family needs more than $9,000.

• The Johnson family needs less than $8,000.

• The Johnson family needs about $8,000, because the point is closer to $8,000.

• The Johnson family needs about $9,000, because the point is closer to $9,000.

A farmer grew four different types of fruit. The fruit that was picked on Saturday afternoon is shown below. - 325 apples - 173 oranges - 218 peaches - 165 plums Which expression shows the best way to estimate the sum of the apples and plums?

• 300 + 170

• 300 + 100

• 300 + 160

• 300 - 200

Ms. Johnson gave 100 problems to her students to do for homework over the weekend. The table below shows the number of problems that four students got correct. Which expression shows the best way to estimate the difference between Joseph’s and Sandra’s scores?

• 90 - 60

• 90 - 50

• 100 - 60

• 90 + 50

The Lucky Toy Store ordered 154 bottles of bubbles for a children’s festival. The number line represents the number of bottles of bubbles the store bought. If they had 36 bottles remaining at the end of the festival, about how many bottles of bubbles did they hand out?

• 110

• 120

• 190

• None of the above

The Bradley family ordered water balloons for a family reunion. The letter B on the number line represents the number of balloons they bought. About how many water balloons did the family order?

• 200, because point B is less than halfway between 200 and 300

• 300, because point B is more than halfway between 200 and 300

• Both A and B

• None of the above

Sam had 32 dimes in his collection jar. He decided to use 15 dimes to buy a candy bar. What is the best estimate for the number of dimes Sam has left?

• 20

• 10

• 30

• 50

Suzie works at a local pizza restaurant. The amount of money she earned working last week is represented by the letter P on the number line.

If she earns the same amount each week, about how much money will Suzie have after 2 weeks?

• $90, because point P is more than halfway between 80 and 90

• $160, because point P is less than halfway between 80 and 90

• $80, because point P is less than halfway between 80 and 90

• $180, because point P is more than halfway between 80 and 90

A soccer team had 128 ounces of water to drink during their game. They drank 112 ounces of the water. Which is the best way to estimate the amount of water left?

• 130 + 110

• 120 – 110

• 130 – 100

• 130 – 110

Point K on the number line represents the number of people who work at a large company. Which statement best describes the number of people who work at the company?

• The number of people is less than 1,000.

• The number of people is greater than 2,000.

• The number of people is about 2,000, because the point is closer to 2,000.

• The number of people is about 1,000, because the point is closer to 1,000.

Ms. Coyle had 312 pencils at the beginning of the year for her students to use. By the middle of the year, they had used 127 of the pencils. Which expression can be used to find about how many pencils Ms. Coyle had left, if the numbers are rounded to the nearest ten or hundred?

• 300 – 200

• 310 – 120

• 300 – 130

• 310 – 130