Measuring and Estimating Length: practice solutions, Grade 2 – download the PDF

1 Choose the best unit ★★★

1. A bean is tiny, so use centimeters.
2. A hallway is long, so use feet.
3. A playground is very wide, so use meters.
4. A notebook is small, so use inches.

2 Read the ruler ★★★

The marker starts at 0 and ends at the 6 mark. Each step is 1 inch.

The marker is 6 inches long.

3 A strip that does not start at 0 ★★★

The strip starts at 3 and ends at 8. Subtract: \(8 - 3 = 5\).

The paper strip is 5 centimeters long. (If you said 8, you forgot that it did not start at 0.)

4 Matching units ★★★

1. \(1\text{ foot} = 12\text{ inches}\)
2. \(1\text{ meter} = 100\text{ centimeters}\)
3. \(1\text{ yard} = 3\text{ feet}\)
4. 2 feet is two groups of 12 inches: \(12 + 12 = 24\), so 2 feet = 24 inches.

5 Which is longer? ★★★

1. 1 foot is 12 inches and \(12 > 8\), so 1 foot is longer.
2. 2 feet is 24 inches and \(24 > 20\), so 2 feet is longer.

6 Pick the tool ★★★

1. A pencil is short: use a ruler.
2. A classroom is wide: use a measuring tape.
3. A bookshelf about 3 feet tall is the length of a yardstick: use a yardstick.

7 True or false? ★★★

1. True. A foot is 12 inches.
2. False. A meter stick is about 39 inches, a little longer than a yardstick (36 inches).
3. True. That is the definition of a meter.
4. True. A centimeter is a small unit, so you need a bigger number of them.

8 Same desk, two units ★★★

2 feet is 24 inches, because \(12 + 12 = 24\). Lena gets 2 feet.

The number is smaller because a foot is a longer unit than an inch, so you need fewer of them.

9 Who guessed best? ★★★

Mia: \(10 - 8 = 2\) inches away. Leo: \(11 - 10 = 1\) inch away.

Leo’s estimate was closer, because 1 is less than 2.

10 Joining ribbons ★★★

Add the lengths: \(15 + 28 = 43\).

The new ribbon is 43 centimeters long.

11 Cutting a rope ★★★

Subtract: \(45 - 18 = 27\).

The rope is now 27 inches long.

12 Red and blue yarn ★★★

1. \(52 - 36 = 16\). The red yarn is 16 centimeters longer.
2. \(36 + 52 = 88\). Together they are 88 centimeters long.

13 The frog jump ★★★

Start at 0, hop 25, then hop 14 more: \(25 + 14 = 39\).

The frog lands at 39 inches.

14 Reading a line plot ★★★

1. There are 3 Xs above 6, so 3 plants.
2. Above 7 there are 2 Xs, above 8 there is 1 and above 9 there is 1: \(2 + 1 + 1 = 4\). 4 plants.
3. The tallest is 9 inches and the shortest is 4 inches: \(9 - 4 = 5\). 5 inches taller.
4. \(1 + 2 + 3 + 2 + 1 + 1 = 10\). 10 plants were measured.

15 Make a line plot ★★★

1. 3 cm: 2 leaves, 4 cm: 4 leaves, 5 cm: 3 leaves, 6 cm: 1 leaf. Check: \(2 + 4 + 3 + 1 = 10\).
2. Draw a number line from 3 to 6, then put 2 Xs above 3, 4 Xs above 4, 3 Xs above 5 and 1 X above 6. Add the unit under the line.

3. The tallest stack is above 4, so the most common length is 4 centimeters.
4. \(3 + 1 = 4\), so 4 leaves are 5 centimeters or longer.

16 Building a fence ★★★

1. \(24 + 24 + 17 = 65\). The fence was 65 inches long.
2. \(90 - 65 = 25\). The fourth board is 25 inches long.

17 Jumping contest ★★★

Change feet to inches: \(3 \times 12 = 36\), or \(12 + 12 + 12 = 36\). Maya jumped 36 inches.

Compare: \(36 > 30\), and \(36 - 30 = 6\).

Maya jumped farther, by 6 inches.

18 Three snakes ★★★

1. 58, 66, 74. The order is 58 cm, 66 cm, 74 cm.
2. \(74 - 58 = 16\). The longest snake is 16 centimeters longer.

19 Find the mistake ★★★

Sam read only the end mark. The pencil did not start at 0.

The correct length is \(8 - 1 = 7\), so the pencil is 7 inches long.

20 Two scarves ★★★

1. \(63 - 27 = 36\). The blue scarf is 36 centimeters long.
2. \(63 + 36 = 99\). Together they are 99 centimeters long.

21 The one-meter ribbon ★★★

1 meter is 100 centimeters. The two pieces together are \(35 + 28 = 63\) centimeters.

\(100 - 63 = 37\). 37 centimeters of ribbon are left.