Addition within 100
- 1. Whole Numbers Addition Within 100 What will we learn today? • Adding two 2-digit numbers • Adding numbers using formal algorithm • Solving 2-step word problems involving addition
- 2. 31 + 20 = _____ Tens Ones Step 1 : Add the ones. 3 1 1 + 0 = 1 + 2 0 Step 2 : Add the tens. 3 + 2 = 5 5 1
- 3. 58 + 9 = _____ Tens Ones Step 1 : Add the ones. 5 8 8 + 9 = 17 1 You cannot have 2 digits on the same column, so you need to do renaming. + 9 17 = 1 ten 7 0nes You need to add the 1 ten to the tens place. 6 7 Step 2 : Add the tens. 5 + 1 = 6
- 4. Word Problem Mrs Tan baked 26 pies. Mrs Lee baked 5 more pies than Mrs Tan. How many pies did Mrs Tan and Mrs Lee bake in all? 1 26 + 5 = 31 2 6 3 1 + 5 +2 6 31 + 26 = 57 3 1 5 7 They baked 57 pies in all.
- 5. Are you ready to try out the questions?