4th Grade: Add and Subtract different measurement units

Add and Subtract different measurement units

​ When we add or subtract measurement units, we always need to make sure to convert that unit. If we need to convert, we change the bigger unit. If we don't need to convert, simply add or subtract the numbers with the unit the question wants at the end.

​If we don't need to convert, simply add the numbers with the given unit at the end. Example:

​1 gal + 6 gal + 7 gal = 14 gal

​If we need to convert, change the bigger unit to the smaller unit.

Example:

​Let us do a problem together.

​12 quarts + 2 quarts left over = (14 quarts + 16 quarts) + the 2 quarts = 32 quarts

​I think you are ready to do this on your own.

​You are given 1 minute to do each question.

Each question is 8 points each.

Multiple Choice

Solve the following equation:

$$\left(6\ \frac{1}{2}gal\ +\ 5\ gal\right)\ -\frac{2}{4}gal$$

• 26 gallons

• 16 gallons

• 11 gallons

• 19 gallons

Multiple Choice

Maria has $$6\ \frac{2}{4}$$ gallon of milk in her freezer. Within the past 8 months, she drank 6 quarts of milk. Today, she has dranken $$2\ \frac{1}{2}$$ pints of milk. How many pints does Maria have left?

• $$61\ \frac{1}{2}$$ pints

• 25 pints

• $$37\ \frac{1}{2}pints$$

• 16 pints

Open Ended

Note: You are given 5 minutes for this problem.

Liam did the following problem in his notebook:

$$12\ \frac{1}{4}hectograms+8\ \frac{2}{4}decagrams\ +9\ \frac{1}{4}grams$$

Liam wrote this answer:

$$20\ \frac{2}{4}decagrams$$

Describe his error.

Multiple Choice

Solve the expression below:

$$\left(2\ \frac{1}{2}meter+\frac{1}{2}cm\right)-\left(6\ cm+1\ \frac{2}{4}mm\right)$$

• 10.3121 meters

• 2.4565 meters

• 6.2334 meters

• 4.1923 meters

Multiple Choice

Find the value of the unknown amount $$x$$ .

$$\left(32\ \frac{6}{12}meter\ -\ 12\ \frac{3}{12}meter\right)+121\ \frac{4}{12}cm\ =\ x$$

• 29.991 meters

• 21.323 meters

• 15.123 meters

• 21.463 meters