MAFS.5.NBT.2.6: Find whole-number quotients of whole numbers with up to four-digit dividends and two-digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.
MAFS.5.NBT.2.5: Fluently multiply multi-digit whole numbers using the standard algorithm.
In 4th grade, students explored and developed strategies based on place value for dividing multi-digit numbers by a 1-digit divisor. In this Unit, students will extend this work to dividing by 2-digit divisors. Though this standard does not specifically state students should solve division problems within context, by setting the skill in a problem scenario, students are provided with meaningful context for the computation, and to continue to interpret remainders when they occur.
Students should visualize the process using models, drawings, and equations to connect to place value understanding. Connecting the division procedure to estimation also helps students establish the reasonableness of their quotients and builds their number sense.
Students should be provided experiences to use various strategies depending on the division situation. When faced with division problems, students might use base-ten blocks, do repeated subtraction, create rectangular models, build up to the dividend through multiplication, or use partial quotients. It is not necessary for every student to solve in every way, however, students should have opportunities to compare and contrast strategies, make connections, and look for efficiency. By sharing methods, discussing their thinking, and justifying approaches, students build a strong understanding of the division process rather than simply memorizing a series of steps.
It is not the goal of the standard for students to master a particular strategy or division procedure. In 5th grade, it is important for students to use the strategy which makes the most sense to them. The standard algorithm for division (long division) is not introduced until 6th grade.
GCG 1 – Learning Goal: As a Mathematician, I will be able to Represent division using an area model/array model with 2-digit divisors MAFS.5.NBT.2.6
- Step 1: Model division with 1-digit divisors by creating groups with base-ten blocks or base-ten pictures and connect to area models
- Step 2: Apply prior work with division models and strategies to work with compatible dividends and divisors as multiples of 10
- Step 3: Use an area model (base-ten block arrays or open arrays) to model and record division with 2-digit divisors
GCG 2 – Learning Goal: As a Mathematician, I will be able to Use a strategy to divide using 2-digit divisors MAFS.5.NBT.2.6