Operating on mixed numbers combines students’ knowledge of addition and subtraction, converting wholes to fractions, converting mixed numbers to improper fractions, and regrouping. In this activity, students will practice adding and subtracting mixed numbers using visuals to aid their computations.
Adding mixed numbers may look a little daunting at first, but if you break down the mixed numbers into wholes and fractions, into pictures, or into improper fractions, everything starts to come together.
Be careful with subtraction! Students may rewrite the order of the number sentence or regroup incorrectly. Start with pictures, like the fraction circles available on Storyboard That. An interesting exercise would be to have an open discussion about subtracting mixed numbers before teaching it, but use your best judgment with your group of students. It may be better to teach mixed number subtraction explicitly before any misconceptions or bad habits start forming.
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Student Instructions
Create visuals to help you add and subtract mixed numbers.
Set up engaging stations where students rotate through various activities focused on adding and subtracting mixed numbers using manipulatives, visuals, and games. This approach provides multiple learning modalities for different learners while reinforcing conceptual understanding.
Provide fraction circles, bars, or tiles to each group. Having physical models available helps students visualize how to combine or separate wholes and fractions when working with mixed numbers.
Create cards or worksheets with mixed number addition and subtraction problems, each paired with pictures or empty spaces for students to draw their own models. Visual cues support deeper understanding and reduce confusion.
Demonstrate how to use the manipulatives, solve a problem, and record answers at every station. Clear modeling helps students know exactly what is expected and builds confidence before independent work.
Guide students in discussing strategies and challenges they faced at each station. Reflection consolidates learning and encourages students to articulate their thinking about mixed numbers.
Breaking mixed numbers into wholes and fractions, using visual aids like fraction circles, and practicing with improper fractions are effective strategies for teaching students in grades 4–5 to add and subtract mixed numbers. Visual models help clarify regrouping and make computations less intimidating.
To add mixed numbers with different denominators, find a common denominator for the fractional parts, convert the fractions, add the fractions and wholes separately, then simplify if needed. Visuals or picture models can help students understand each step.
Common mistakes include regrouping incorrectly, subtracting fractions before wholes, or reversing the order of the numbers. Using visual models and explicit instruction helps prevent these errors and supports deeper understanding.
Visuals like fraction circles and spider maps make abstract concepts concrete, helping students see how wholes and fractions combine or separate. This supports learners who struggle with computation alone and builds conceptual understanding.
Multiply the whole number by the denominator, add the numerator, and place the result over the original denominator. For example, 2 1/3 = (2×3)+1 = 7/3.