﻿WEBVTT 1 00:00:03.066 --> 00:00:05.032 Today we will look closely at 2 00:00:05.033 --> 00:00:08.666 2x2=4 to understand how it can be 3 00:00:08.666 --> 00:00:11.199 helpful in math. Every 4 00:00:11.200 --> 00:00:13.400 multiplication fact is made up of a 5 00:00:13.400 --> 00:00:16.633 factor, a factor, and a product. 6 00:00:16.633 --> 00:00:19.266 For this lesson, the factor two, 7 00:00:19.266 --> 00:00:22.099 times the factor two, equals the 8 00:00:22.100 --> 00:00:24.700 product, four. One way to 9 00:00:24.700 --> 00:00:28.266 understand 2x2=4 is to think of it 10 00:00:28.266 --> 00:00:31.166 as two groups of two. In this 11 00:00:31.166 --> 00:00:33.799 example, we have two groups with 12 00:00:33.800 --> 00:00:37.366 two in each group. Or two groups 13 00:00:37.366 --> 00:00:38.966 of two. 14 00:00:40.233 --> 00:00:46.533 One, two groups with one, two in 15 00:00:46.533 --> 00:00:47.599 each group. 16 00:00:47.600 --> 00:00:49.633 Since there are two in each 17 00:00:49.633 --> 00:00:51.466 group, we can find the total 18 00:00:51.466 --> 00:00:53.366 number of items by adding two 19 00:00:53.366 --> 00:00:56.466 together two times, which equals 20 00:00:56.466 --> 00:01:00.766 four. 2x2 is the fast way of adding 21 00:01:00.766 --> 00:01:04.366 two two times. Adding the same 22 00:01:04.366 --> 00:01:06.932 number together repeatedly is 23 00:01:06.933 --> 00:01:11.233 called repeated addition. Many 24 00:01:11.233 --> 00:01:13.333 math books use an array to help 25 00:01:13.333 --> 00:01:17.599 visualize multiplication. 2x2 would 26 00:01:17.600 --> 00:01:21.866 be two rows of two. 2x2 would be 27 00:01:21.866 --> 00:01:26.232 called a two-by-two array. An 28 00:01:26.233 --> 00:01:28.633 array helps us visualize how 29 00:01:28.633 --> 00:01:31.599 2x2=4. 30 00:01:31.600 --> 00:01:35.766 Another way to visualize 2x2=4 is 31 00:01:35.766 --> 00:01:38.932 to use a number line. 2x2 on a 32 00:01:38.933 --> 00:01:40.599 number line can be shown as two 33 00:01:40.600 --> 00:01:44.166 equal jumps of two steps. Starting 34 00:01:44.166 --> 00:01:45.899 with zero, we make two equal 35 00:01:45.900 --> 00:01:48.733 jumps of two steps each along the 36 00:01:48.733 --> 00:01:51.266 line. Since we are jumping along 37 00:01:51.266 --> 00:01:53.032 in groups of two, we can use 38 00:01:53.033 --> 00:01:56.333 repeated addition here too. Or two 39 00:01:56.333 --> 00:01:58.666 added together two times, which 40 00:01:58.666 --> 00:02:00.099 equals four. 41 00:02:00.266 --> 00:02:02.166 So now we understand why 42 00:02:02.166 --> 00:02:05.632 2x2=4, but to help us remember 43 00:02:05.633 --> 00:02:07.766 the answer quickly and easily, I 44 00:02:07.766 --> 00:02:10.632 like to use a picture and a story. 45 00:02:10.633 --> 00:02:12.633 What picture helps us remember 46 00:02:12.633 --> 00:02:18.233 the answer to 2x2? Yup! The 47 00:02:18.233 --> 00:02:21.133 picture of the two shoes, two and 48 00:02:21.133 --> 00:02:27.499 two, on the floor, four. If you didn't 49 00:02:27.500 --> 00:02:29.466 remember the picture quickly, you 50 00:02:29.466 --> 00:02:30.899 might want to watch the first video 51 00:02:30.900 --> 00:02:33.066 again. Thanks for spending time 52 00:02:33.066 --> 00:02:34.866 with me again, remember, I'm 53 00:02:34.866 --> 00:02:35.999 always here if you need more 54 00:02:36.000 --> 00:02:38.566 help. Bye!