## TOPIC 2 TEST - WEDNESDAY, SEPTEMBER 24TH

2-1 Mental Math* Students compute sums and differences mentally (5.NBT.7) * - numbers can be added in any order and the sum will remain the same Commutative Property Ex. 5+2=7 or 2+5=7 * - you can change the grouping of addends and the sum will remain the sameAssociate PropertyEx. (2+3)+4=9 or 2+(3+4)=9 * - a way or rounding that gives numbers that are easy to computer mentallyCompatible NumbersEx. 23+77 = would estimate to 25+75=100 |
2-2 Rounding Whole Numbers and Decimals* Students round whole numbers through millions and decimals through thousandths (5.NBT.4) * 0,1,2,3,4 leave it alone, don't add anymore Ex. 24 - if rounding to the tens place (the 2), look to the right, the digit in the ones place (the 4) tells you to keep the 2 a 2 - so your rounded number would become 20 * 5,6,7,8,9 add one more every time Ex. 378 - if rounding to the hundreds place (the 3) look to the right, the digit in the tens place (the 7) tells you to round up, turn the 3 into a 4 = your rounded number will be 400 * When rounding whole numbers, all of the digits after the place you are rounding to, become zeros * When rounding decimals, all of the digits after the place you are rounding to get dropped, zeros at the end of a decimal have no value |
2-3 Estimating Sums and Differences* Students use rounding and compatible numbers to estimate sums and differences of whole numbers and decimals (5.NBT.7) |
2-4 Modeling Addition and Subtraction of Decimals* Students will add and subtract decimals in tenths and hundredths using models (5.NBt.7) Ex. .7 + .44 * In the model below, each color represents a different part of the equation. The turquoise is equal to seven tenths (each column is worth one tenth) the purple is equal to forty-four hundredths (each box is equal to one hundredth) * To get the total, you must add up all of the colored sections * .7+.44=1.14 - the hundredths tables that is completely filled represents one whole * 1.54 - .74
*The purple represents the total amount (1.54), the boxes that are "X" out represent the amount that is being subtracted (.74) * To find the solution, count the boxes that remain purple with no "X" * 1.54-.74=.8 |

2.5 Problem Solving: Draw a Picture and Write and Equation*Students use pictures and write equations to help them solve problems (5.NBT.7) |
2.6 Adding Decimals* Students compute sums of decimals involving tenths, hundredths, and thousandths (5.NBT.7) * NUMBER ONE RULE...ALWAYS LINE UP THE DECIMALS POINTS * If you do not line up the decimals points you will not be adding digits in the same place value * Key words for addition - SUM, TOTAL, IN ALL, HOW MUCH/MANY, ALL TOGETHER |
2.7 Subtracting Decimals*Students compute differences of decimals involving tenths, hundredths, and thousandths (5.NBT.7) * NUMBER ONE RULE...ALWAYS LINE UP THE DECIMALS POINTS * If you do not line up the decimals points you will not be subtracting digits in the same place value * If one number has fewer decimals than the other, add zeros to make them have an equal number of digits. This will ensure that you are subtracting properly * Key words for subtraction - DIFFERENCE, HOW MANY MORE, HOW MANY FEWER, HOW MUCH LESS |
2.8 Problem Solving: Multi-Step Problems* Students use multiple steps to solve a variety of problems (5.NBT.7) |