Subtracting by Using Addition: Mastering 2-Digit Subtraction

This video tutorial explains how to subtract two-digit numbers using addition. It begins by introducing subtraction as the opposite of addition and reviews basic subtraction concepts. The tutorial demonstrates subtraction using base ten blocks and open number lines, emphasizing the counting up method. Several examples illustrate how to rewrite subtraction problems as addition sentences, making it easier to find the difference between numbers. The video concludes with a detailed example of subtracting 86 minus 27 using the counting up method.

What is the primary goal when performing subtraction?

• To divide two numbers

• To find the difference between two numbers

• To find the sum of two numbers

• To multiply two numbers

How can subtraction be modeled using base ten blocks?

• By adding blocks

• By removing blocks

• By multiplying blocks

• By dividing blocks

What is a common misunderstanding about the digit 8 in the number 87?

• It represents 8 tens

• It represents 800

• It represents 80

• It represents 8 ones

When using an open number line, what is a helpful strategy for counting up?

• Counting by tens

• Counting by hundreds

• Counting by twos

• Counting by ones

What is the result of 63 minus 32 when using the counting up method?

• 32

• 29

• 30

• 31

How can you simplify counting up from 27 to 86?

• By counting up to the nearest hundred

• By counting up to the nearest ten

• By counting up to the nearest five

• By counting up to the nearest one

What is the final result of 86 minus 27 using the counting up method?

• 61

• 58

• 59

• 60