This video explains place value in decimal numbers. Practice problems are available. [4:00]

Sal shows 42 as 4 tens and 2 ones using a visual demonstration. Includes a video, transcript, and question and answer section. [4:18]

Sal uses the number 37 to explain why we use a 'ones place' and a 'tens place' when writing numbers. Includes a video, transcript, and question and answer section. [5:58]

Sal compares 394 and 397 and then writes the expression using < or >. Includes a video, transcript, and question and answer section. [2:04]

Sal shows 25 as 2 tens and 5 ones using a visual demonstration. Includes a video, transcript, and question and answer section. [2:54]

Sal looks at the 1 in each teen number and thinks about what it really means. Includes a video, transcript, and question and answer section. [2:59]

Sal breaks the number 18 into 10 and 8 using monkeys. Includes a video, transcript, and question and answer section. [2:57]

Sal shows how to subtract 357-251 (without regrouping) using place value. Includes a video, transcript, and question and answer section. [2:56]

Sal demonstrates visually how to subtract 3-digit numbers by subtracting ones, tens, and hundreds. Includes a video, transcript, and question and answer section. [3:11]

Sal shows some techniques for doing mental addition, such as making groups of 10 and 100. Includes a video, transcript, and question and answer section. [7:27]

Sal rewrites three-digit addition problems to make them easier to solve. Includes a video, transcript, and question and answer section. [3:57]

Sal subtracts 1, 10, or 100 from a number using a visual demonstration. Includes a video, transcript, and question and answer section. [4:10]

Sal shows ways to break up three-digit addition problems using place value. Includes a video, transcript, and question and answer section. [3:41]

Sal demonstrates how to subtract 23 from 65 (without regrouping) by thinking about tens and ones. Includes a video, transcript, and question and answer section. [2:36]

Sal subtracts 4 from 46 by thinking about place value. Includes a video, transcript, and question and answer section. [2:44]

Sal demonstrates how to subtract 40 from 65 by thinking about place value. Includes a video, transcript, and question and answer section. [2:36]

Sal demonstrates the difference between subtracting 1 and subtracting 10 from 27. Includes a video, transcript, and question and answer section. [2:31]

Sal visually demonstrates how to add 327 + 251 (without regrouping) using place value. Includes a video, transcript, and question and answer section. [2:39]

Sal adds 1, 10, or 100 to 235. Includes a video, transcript, and question and answer section. [3:58]

Sal adds 3-digit numbers by adding ones, tens, and hundreds. Includes a video, transcript, and question and answer section. [3:36]

Sal shows various ways of subtracting 25 from 83 by thinking about tens and ones. Includes a video, transcript, and question and answer section. [5:26]

Sal subtracts two-digit numbers (without regrouping) by thinking about tens and ones. Includes a video, transcript, and question and answer section. [2:20]

Sal subtracts 35-8 with regrouping. Includes a video, transcript, and question and answer section. [3:10]

Watch network engineer Diana Tootle explain how she uses math in her work in this video from KAET. In the accompanying classroom activity, students watch the video and then complete an activity involving an aspect of math that Ms. Tootle...