Estimating Fractions Worksheet

**Page 1**

1.

Estimate:

1,636 ÷ 38

1,636 ÷ 38

a. | 100 | ||

b. | 30 | ||

c. | 60 | ||

d. | 41 |

38

1636 ÷ 38

Correct answer : (4)

2.

Which statement leads you through to estimate mentally the quotient of $\frac{191}{25}$ to the nearest tenth?

I. The fraction is easily convertible to a fraction with a denominator of 100.

II. Look for numbers that multiply with 25 to give 191.

III. Use a calculator.

I. The fraction is easily convertible to a fraction with a denominator of 100.

II. Look for numbers that multiply with 25 to give 191.

III. Use a calculator.

a. | I | ||

b. | I and II | ||

c. | III | ||

d. | II |

[Round down 7.64 to the nearest tenths.]

Statement II talks about 'trial and error' method. You keep trying different numbers until you find the relevant one, and sometimes you may not find one.

Statement III is ruled out, as we need to estimate the quotient mentally.

Among the statements given, statement I would lead us through the estimation.

Correct answer : (1)

3.

Estimate, using compatible numbers, the sum of $\frac{46}{22}$ and $\frac{35}{71}$ to the nearest tenth.

a. | 2.5 | ||

b. | 2.0 | ||

c. | 3.0 | ||

d. | 2.3 |

[46 is close to 44 and is compatible with 22.]

[70 is close to 71 and is compatible with 35.]

Correct answer : (1)

4.

Alice bought a sack of potatoes that weighs $\frac{1}{9}$ lb and a sack of tomatoes that weighs $\frac{7}{8}$ lb. Estimate the total weight of the vegetables.

a. | $1\frac{3}{8}$ lb | ||

b. | $3\frac{1}{2}$ lb | ||

c. | 4 lb | ||

d. | 1 lb |

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Estimated total weight of the vegetables = 0 + 1 = 1 lb

Correct answer : (4)

5.

A can holds $12\frac{4}{9}$ quarts of liquid. If $\frac{1}{3}$ of it is water, estimate the quantity of water in the can.

a. | 4 quarts | ||

b. | 8 quarts | ||

c. | 12 quarts | ||

d. | 3 quarts |

The estimated quantity of water in the can = 12 ×

Correct answer : (1)

6.

Estimate the product of $\frac{19}{6}$ and 11.

a. | 33 | ||

b. | 114 | ||

c. | 66 | ||

d. | 22 |

3 × 11 = 33

So, the approximate product of

Correct answer : (1)

7.

$4\frac{3}{4}$ ${cm}^{3}$ of wood is required to make one box. Estimate the wood required for making 5 boxes.

a. | 60 ${cm}^{3}$ | ||

b. | 5 ${cm}^{3}$ | ||

c. | 25 ${cm}^{3}$ | ||

d. | 75 ${cm}^{3}$ |

Approximately 5

Wood required for making 5 boxes = 5 × 5 = 25

So, approximately 25

Correct answer : (3)

8.

A whale gains a weight of $8\frac{1}{3}$ lb in $4\frac{1}{3}$ months. Estimate the weight gained by the whale in one month.

a. | 2 lb | ||

b. | 18 lb | ||

c. | 4 lb | ||

d. | 12 lb |

So, the approximate weight gained by the whale in one month is 2 lb.

Correct answer : (1)

9.

Estimate the quotient of 12.125 divided by 0.8112.

a. | 12 | ||

b. | 8 | ||

c. | 18 | ||

d. | 15 |

[Estimating the quotient of two decimals is to round both the divisor and dividend to one non-zero digit, and then divide the rounded decimals.]

12 ÷ 0.8 = 15

So, the estimated quotient of 12.125 divided by 0.8112 is 15.

Correct answer : (4)

10.

Cost of 3 m of a wire is $14.87. Estimate the cost of 8.17 m of the wire.

a. | $40 | ||

b. | $66 | ||

c. | $72 | ||

d. | $36 |

Cost of 3 m of wire

So, cost of 1 m of wire

8.17 m

Cost of 8 m of wire

So, the estimated cost of 8.17 m of wire is $40.

Correct answer : (1)