Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 – 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).
There are 18 videos in this category and 0 videos in 0 subcategories.
Category Videos

Not Right For WatchKnowLearn
Ages: 5  11
10312 Views:

Addition and subtraction facts that use the same numbers are related. 6+5 =11 and 11  5 = 6 are related facts. Use related facts to solve problems. User clicks through the slides.
May 14, 2010 at 02:04 PM


Not Right For WatchKnowLearn
Ages: 7  12
7527 Views:

Inverse operations are pairs of mathematical operations, like addition and subtraction, that can undo eachother. You can learn how to do it by using fact families. This cartoon animation from StudyJams also includes a short, selfchecking quiz.
June 18, 2011 at 10:26 PM


Not Right For WatchKnowLearn
Ages: 8  14
6232 Views:

When Diffy opens, there are four black numbers placed at the corners of a black square. Your first goal is to fill in the four blanks in the blue circles in the middle of each side of the black square.
Start with any side of the black square and cli...ck in the blank in the blue circle on that side and type in the difference of the black numbers on that side (the larger black number less the smaller one). So if the black numbers on the top side of the black square were 7 and 12, we would type 5 (= 12 – 7) in the blue circle between the 7 and the 12.
Note: There are more directions on the right side.
[more]
May 9, 2010 at 11:11 AM


Not Right For WatchKnowLearn
Ages: 8  12
6936 Views:

Students will learn different strategies to determine the product of a multiplication problem. Skip counting on a number line, drawing a picture, drawing an array and writing a multiplication sentence are different strategies for finding the product.... User clicks through the slides.
[more]
May 20, 2010 at 04:12 PM


Not Right For WatchKnowLearn
Ages: 4  7
6834 Views:

Students learn to write fact family problems. Fact families all use the same number. Using a whole, part, part mat, students use cube trains to write two different addition problems using the same numbers 2, 8 and 10 (2+8=10, 8+2=10). For the subt...raction problems, students use the same cube trains but start with the whole (10) and then break it down into the two parts (2, 8). Write the subtraction sentences with the same numbers 2, 8 and 10 (108=2, 102=8).
[more]
May 14, 2010 at 01:29 PM


Not Right For WatchKnowLearn
Ages: 8  12
6418 Views:

Students will learn to use the properties of addition to make addition easier. The associative property says that addends can be grouped in any order. Changing the order that numbers are added does not change the sum. The sum of zero plus a number..., if that number.
[more]
May 20, 2010 at 03:58 PM


Not Right For WatchKnowLearn
Ages: 5  11
7318 Views:

A fact family uses the same three numbers to make addition and subtraction problems such as 7+2=9, 2+7=9, 92=7, 97=2.
May 20, 2010 at 01:59 PM


Not Right For WatchKnowLearn
Ages: 6  9
2329 Views:

Using knowledge of addition facts, students will learn how to use related facts or fact families to solve the problem. Related facts or fact families, use the same 3 numbers. User clicks through the slides.
May 20, 2010 at 02:15 PM


Not Right For WatchKnowLearn
Ages: 18  18
6718 Views:

Learn how to play and teach this great game for practicing arithmetic with an expert teaching tips in this kids math games video clip. This game can be played for practicing addition, subtraction, multiplication, or division skills. This is a fun g...ame that is easily learned and played. (01:49)
[more]
March 3, 2010 at 10:30 PM


Not Right For WatchKnowLearn
Ages: 5  8
3971 Views:

Students learn to add three onedigit numbers. Numbers can be added in any order. Look for an addition fact that you know, then add.
May 14, 2010 at 01:58 PM
