# Question Video: Subtracting One-Digit Numbers from Two-Digit Numbers Using Place Value Blocks Mathematics • 1st Grade

Mia is calculating 33 − 4. She showed 33 using place value blocks. After she regroups and subtracts 4, how many tens and ones will be left?

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### Video Transcript

Mia is calculating 33 subtract four. She showed 33 using place value blocks. After she regroups and subtracts four, how many tens and ones will be left?

In this question, we have to help Mia calculate 33 subtract four. The number 33 is a two-digit number. And Mia’s modeled this using place value blocks. 33 has three 10s, worth 30, and three ones, which are worth three.

The second part of the question tells us that Mia has to regroup to subtract four. We know that four is more than three. There are not enough ones in the number 33 to subtract four from. So we need to take one of our tens and exchange it for 10 ones. Now we have two 10s and 13 ones. Now we have enough ones to subtract our four from. 13 take away four is nine. We’ve got nine ones left. We had three 10s. We exchanged one 10, so we only have two 10s left. And there’s nothing to subtract from these two 10s in the tens place. So 33 subtract four is 29. After Mia regroups and subtracts four, she will have two 10s and nine ones left.