Add 2-Digit Numbers using Number Lines
π¦ The giant leap! When numbers are big, our frog needs to take Giant Ten-Jumps and little One-Hops.
Do this: Read the concept below, then try the quiz or activity.
Concept
A regular number line would be way too long. But wait! There is a huge shortcut.
π― The "Jump and Hop" Strategy: Example: 24 + 32 = ? Instead of hopping right 32 times, we break 32 into tens (30) and ones (2).
1. Start at the first number: Put a dot exactly on 24. 2. Take Giant Ten-Jumps: 32 has 3 tens. Take THREE giant jumps of 10! * Jump +10 to 34. * Jump +10 to 44. * Jump +10 to 54. 3. Take Little One-Hops: 32 has 2 ones. Take TWO little hops! * Hop +1 to 55. * Hop +1 to 56. * You landed on 56! So, 24 + 32 = 56.
Try it
Take the giant leaps!
Instructions: Imagine the number line. Take giant leaps of 10, then tiny hops of 1!
Problem 1: 45 + 23 = ? * Start at 45. * Take TWO giant +10 leaps: 45 -> 55 -> ___ * Take THREE tiny +1 hops: 65 -> 66 -> 67 -> ___ * Answer: ___
Problem 2: 31 + 14 = ? * Start at 31. * Take ONE +10 leap: ___ * Take FOUR +1 hops: ___ * Answer: ___
Problem 3: 62 + 25 = ? * Answer: ___