Christmas Maths Challenge

Here is a problem which might require a little perseverance.  There is more than one solution.

Make a Century

By putting arithmetical signs (+ , - , x ) in suitable places between the digits make the following sum correct:

1   2   3   4   5   6   7   8   9  =  100

Note: The digits must remain in counting order but the spaces may be removed to make two or three digit numbers.  For example, the space between the 2 and 3 can be eliminated to make 23.  Brackets may be used if necessary.

Bring your solution(s) to Mrs. Hopkins by Thursday January 8th. The person who can find the most solutions will be able to have an extra session helping in Nursery (during lesson time).

Rudolph's Nose Solution

1. He will need 9 light bulbs.  (There are 3 sets of 8 hours in 24 hours.  Rudolph needs 3 new bulbs for each set of 8 hours. 3 x 3 = 9)

2. Santa will need to spend £11.25.  (9 x 1.25 = 11.25)

Rudolph's Nose **

1. Rudolph the red-nosed reindeer has 3 red light bulbs in his nose and they blow out every 8 hours.  How many light bulbs will Rudolph need if his nose is going to glow for 24 hours?

2. If Rudolph's bulbs cost £1.25 each, how much will Santa need to spend for 24 hours worth of bulbs?

Santa Buys Name Tags Solutions

a) Rudolph, Prancer and Blitzen have the most expensive names.

b) Comet, Vixen and Cupid have the least expensive names.

(Did anyone notice that all the names have 2 vowels so you only need to look at the number of consonants to discover who had the most or least expensive names?)

c) Dasher = £29.40
Prancer = £35.10
Comet = £23.70
Donner = £29.40
Rudolph = £35.10
Dancer = £29.40
Vixen = £23.70
Cupid = £23.70
Blitzen = £35.10

Santa Buys Name Tags *

Santa decides to buy name tags for his reindeer.  The names are:
Dasher, Dancer, Prancer, Vixen. Comet, Cupid, Donner, Blitzen and Rudolph.

For each name tag, vowels cost £3.30 and consonants cost £5.70.

a) Which 3 reindeer are tied for the most expensive names?
b) Which 3 reindeer are tied for the least expensive names?
c) How much did Santa pay for the name tags for all 9 reindeer?

Variation - Change the cost of the letters to make the challenge easier or more difficult.  For example, younger children may be able to add together whole pounds (ie. vowels = £3 and consonants £5) instead of working with pounds and pence together.

Make 24! Solutions

A) 3 x 4 + 7 + 5

B) 11 + 10 + (6 ÷ 2)

C) 6 x 8 ÷ 2 x 1

D) 8 x [7 – (3+1)]

E) 5 x 6 – 4 - 2