Add and subtract tens

Learning Objectives Identify numbers that are multiples of ten. Add two multiples of ten (e.g., 20 + 40). Subtract a multiple of ten from another (e.g., 70 - 30). Use a number line or blocks to model adding and subtracting tens. Solve simple word problems involving adding and subtracting tens. Explain that adding tens is like adding single digits, but with a zero. Imagine you have 2 boxes of 10 crayons each. What if you get 3 more boxes? How many crayons would you have? 🤔🖍️ Today, we will learn a super trick to add and subtract big numbers like 10, 20, and 30! It's like counting with big steps. This helps us count things much faster. Real-World Applications Counting money in dimes (10 cents each) 🪙 Sharing packs of 10 stickers with friends ✨ Figuring out how...

TermDefinitionExample TensA group of ten things. Numbers like 10, 20, 30, and 40 are all tens.A box with 10 crayons is one ten. 🖍️ Two boxes are two tens, or 20 crayons. Add (+)To put groups together to find the total. We use the plus sign.2 apples + 3 apples = 5 apples. 🍎🍎 + 🍎🍎🍎 = 🍎🍎🍎🍎🍎 Subtract (-)To take some away from a group. We use the minus sign.5 cookies - 2 cookies = 3 cookies. 🍪🍪🍪🍪🍪 - 🍪🍪 = 🍪🍪🍪 Tens PlaceThe spot where the 'tens' digit goes in a number.In the number 40, the 4 is in the tens place. It means 4 groups of ten. Ones PlaceThe spot where the 'ones' digit goes. For our tens, this is always zero!In the number 40, the 0 is in the ones place. It means there are no single ones. EquationA math sentence that uses an equals sign (=) to sh...

Adding Tens Rule A \text{ tens} + B \text{ tens} = (A+B) \text{ tens} To add tens, just add the first digits. Then, put a zero at the end. Subtracting Tens Rule A \text{ tens} - B \text{ tens} = (A-B) \text{ tens} To subtract tens, just subtract the first digits. Then, put a zero at the end.