MAFS.3.OA.3.7 Fluently multiply and divide within 100, using strategies such as the relationship between multiplication and division (e.g., knowing that 8 × 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.
MAFS.3.NBT.1.3 Multiply one-digit whole numbers by multiples of 10 in the range 10–90 (e.g., 9 × 80, 5 × 60) using strategies based on place value and properties of operations.
MAFS.3.OA.4.9 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 number can be decomposed into two equal addends.
Students in this Unit will apply and connect to their understanding of multiplying a 1-digit factor by 10, to include 1-digit groups of multiples of 10s. Students should work with concrete models to understand that multiplying 4 x 30 means having 4 groups of 3 tens, and that is 12 tens or 120, rather than multiplying 4 x 3 and “add a zero at the end.” Teaching shortcuts (like adding a zero at the end) rather than understanding the relationship between the product and its place value does not establish the underlying importance of place value in multiplication.
This Unit can be a chance for a cumulative “Fact Conference” including randomly chosen facts from all fact groups.
GCG 1 – Learning Goal: As a mathematician, I will be able to model and apply generalizations to multiply with multiples of 10
- Step 1: Use base ten blocks and quick pictures to model equal groups of multiples of 10
- Step 2: Identify and explain patterns when multiplying by multiples of 10
- Step 3: Apply patterns and generalizations to multiply with multiples of 10
GCG 2- Learning Goal: As a mathematician, I will be able to demonstrate fluency of multiplication and division facts
- Step 1: Demonstrate fluency of multiplication facts
- Step 2: Demonstrate fluency of division facts