Zearn Math Grade 4, Mission 2: Metric Unit Conversions
In this unit, your child converts metric units of length, mass, and liquid volume, such as kilometers to meters and liters to milliliters, and solves word problems with them. Because metric units work in tens, hundreds, and thousands, this builds directly on the place value and addition and subtraction before it. Multidigit multiplication and division come next.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Mission 2?
- Converting kilometers to meters, meters to centimeters, kilograms to grams, and liters to milliliters, using the fact that they work in thousands or hundreds. Learn more: Converting feet to inches and kilograms to grams
- Adding and subtracting mixed metric measurements, such as 3 kilograms 250 grams minus 1 kilogram 600 grams, to solve word problems. Learn more: Story problems about distance, time, and money
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
Amara buys a 5-pound bag of oranges. How many ounces does the bag weigh?
- 60 ounces
- 21 ounces
- 80 ounces
How you can help
- Read metric labels at the store: a 2-liter bottle holds 2,000 milliliters, so ask your child how many 500-milliliter bottles hold the same amount.
- Weigh things on a kitchen scale in grams, if you have one, and ask your child to rewrite a weight like 1,500 grams as kilograms and grams.
- Talk about distance on a walk: if a loop is 2 kilometers, ask your child how many meters that is, and how far 3 loops would be in meters.
Where kids can get stuck
- Calculating before converting, such as subtracting 250 milliliters from 2 liters as if both numbers used the same unit.
- Multiplying by 100 instead of 1,000 when converting kilometers to meters or kilograms to grams.
- Forgetting to regroup a kilogram as 1,000 grams when subtracting mixed units like 3 kilograms 250 grams minus 1 kilogram 600 grams.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- convert
- To change a measurement to a different unit, like 3 feet to 36 inches.
- metric system
- Measuring units that work in tens, hundreds, and thousands, like meters, grams, and liters.
- kilometer
- A metric unit of length equal to 1,000 meters.
- meter
- A metric unit of length equal to 100 centimeters, a little longer than a yard.
- centimeter
- A small metric unit of length; 100 centimeters make 1 meter.
- kilogram
- A metric unit of mass equal to 1,000 grams.
- gram
- A small metric unit of mass, about the mass of a paper clip.
- liter
- A metric unit of liquid volume equal to 1,000 milliliters.
- milliliter
- A small metric unit of liquid volume; 1,000 milliliters make 1 liter.
Ready to build your child’s confidence with metric conversions?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
Join the club
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Zearn Math Grade 4 Mission 2 cover?
Zearn Math Grade 4 Mission 2 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.