Number Line Hop

Little levels (ages 4 to 6)

1. Hop to the number Hop one pad at a time to five, eight and three.
2. Add by hopping 3 + 2, 4 + 3 and 6 + 2 by hopping forward.
3. Hop back 6 − 2, 9 − 4 and 5 − 3 by hopping backwards.
4. Missing numbers Find where seven, three and nine go when only 0, 5 and 10 are labeled.
5. One big hop Tap the pad for eight, four, ten and two.

Big levels (ages 7 to 9)

1. Big hops of ten Reach 43, 76 and 28 with hops of ten and one.
2. Add tens and ones 25 + 13, 42 + 26, 57 + 21 as big and little hops.
3. Hop back tens and ones 40 − 15, 63 − 22, 90 − 41 hopping back.
4. Halfway between Halfway from 30 to 40, 60 to 70, and 0 to 100.
5. Nearest ten Round 47, 32, 85 and 64 by hopping to the closer ten.
6. Counting by fives Find 35, 15 and 45 on a line that goes up by fives.

The big ideas

• A number line keeps numbers in order. Every number has its own place, one hop apart. That is why you can find a missing number from its neighbors.

• Adding is hopping forward; taking away is hopping back. 3 + 2 means start on 3 and hop forward 2. 6 − 2 means start on 6 and hop back 2. Where you land is the answer.

• Tens are big hops. To get to 43, take four hops of ten and three hops of one. Adding 13 is one big hop and three little ones.

• Halfway means the same distance from both ends. 35 is five hops from 30 and five from 40. 50 is halfway between 0 and 100.

• Rounding means hopping to the closest ten. 47 is closer to 50 than to 40, so it rounds to 50. A number ending in five is exactly in the middle, and the rule is to round up.

Try it at home

1. Floor number line Lay out numbered cards or chalk a line from 0 to 10 and hop along it. Start on 4, hop 3: where are you?
2. Hop back Stand on 8 and hop back 3. Then try 10 take away 4. Say each number as you land on it.
3. Guess the halfway Pick two numbers like 20 and 30 and guess the number halfway between. Check by counting steps from each end.
4. Rounding game Call out numbers like 23, 58 and 75. Hop to the nearest ten and say which way was closer.

Ask after playing

• If Pip starts on 5 and hops forward 4, where does he land?
• Which number is halfway between 10 and 20?
• Does 38 round to 30 or 40? How do you know?