Unit 4 Computing with Whole Numbers

In Unit 4 students will:

  • Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations and/or the relationship between addition and subtraction (a range of algorithms may be used).
  • Fluently multiply and divide within 100 using strategies such as the relationship between multiplication and division (e.g. knowing that 8 x 5 = 40, one knows 40 ÷ 5 = 8) or properties of operations. By the end of Grade 3, know from memory all products of two one-digit numbers.
  • Multiply one-digit whole numbers by multiples of 10 in the range 10-90 (e.g., 9 x 80, 5 x 60) using strategies based on place value and properties of operations.
  • Use place value understanding to round whole numbers to the nearest 10 or 100.
  •  Identify arithmetic patterns (including patterns in the addition table or multiplication table), and explain them using properties of operations. For example, observe that 4 times a number is always even, and explain why 4 times a numbers can be decomposed into two equal addends.
  • Solve two-step word problems using the four operations. Represent these problems using equations with letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding.

By the end of Unit 4 your child should be able to answer the following questions:

  • How can place value help me become more fluent with multiplication and division?
  • What strategies will I use to help me memorize all single digit multiplication and division facts?


The following videos will explain some of the topics covered in Unit 4.

  • Place Value Review

  • Expanded Form

  • Comparing and Ordering Numbers to 1,000

  • Round 2-Digit Numbers to the Nearest Ten

  • Round 3 Digit Numbers to the Nearest Ten

  • Round to the Nearest Hundred

  • 2- Digit Addition on an Open Number Line

  • 3-Digit Addition on an Open Number Line

  • Compensation Strategy for Addition

Subtracting: Regrouping from zero

  • Subtracting on an Open Number Line

  •  Relating Multiplication and Division with Multiples of Ten

  • Function Tables

  • To play a Function Table Game